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Canadian Journal of Basic and Applied Sciences
©PEARL publication, 2014
CJBAS Vol. 02(02), 46-63, 2014
ISSN 2292-3381
Equilibrium configurations of cantilever columns under a tip-concentrated
subtangential follower force
M. Mutyalarao a, D. Bharathi a, B. Nageswara Rao b
a Department of Engineering Mathematics, College of Engineering, Andhra University, Visakhapatnam - 530003,
India b Department of Mechanical Engineering, School of Civil and Mechanical Sciences, KL University, Green Fields,
Vaddeswaram – 522 502, India
Keywords: Abstract
Cantilever column,
Large-deflections,
Tip-concentrated load,
Tip-angle,
Subtangential,
parameter
Studies are made on the post-buckling behavior of a cantilever column subjected to a
tip-concentrated subtangential follower force. The formulation of the problem results
in non-linear ordinary differential equations amenable to numerical integration. A
relation is obtained for the applied load in terms of the subtangential parameter and
the tip-angle of the column. Also identified the range of the load parameter for which
one can get multiple solutions.
1. Introduction
One of the interesting and oldest problems of elastomechanics is the determination of
equilibrium shapes of a cantilever beam under a tip-concentrated load. Assuming that the curvature
of the beam is proportional to the bending moment, Euler provided a differential equation with an
infinite series solution for the deformed shape of the beam and also classified all equilibrium states
(see Antman [1]). The problem of nonlinear bending of cantilever beams has been studied by many
researchers [2-9].
Slender structural components, such as beams and columns, constitute basic parts of many
structures. For example, slender cantilever columns are used extensively as struts, carrying
compressive loads. In the analysis of such structures, nonlinearities arise due to large deformations
and material properties. The determination of elastic curve of a column is essential since it is often
required that not only stresses induced in the column should not exceed the allowable stress but also
the maximum deflection of the column should not be greater than a certain predetermined value
depending on the operating conditions of the column. Study of such structures under the action of
non-conservative forces is of particular importance in modern engineering practice.
Corresponding Author:
E-mail, [email protected] – Tel, (+91) 86456948 – Fax, (+91) 8645247249
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
47
Timoshenko and Gere [10] have studied the Euler’s column and solved the problem in terms of
elliptical integrals. Chen [11] has proposed a new integral approach for large deflection cantilever
columns. Application of the Euler method in these studies is used mainly due to the external forces
which are acting on the body considered to be conservative. Bolotin [12] gives the extension of the
Euler method to the problem of the stability of a column under the action of a compressive force
(follower force) which after deformation rotates together with the tip of the column and at all times
remains tangential to its deformed axis. The stability of nonconservative systems has extensively
studied [13-24].
The presence of nonconservative loads makes the linearization of equation system
mathematically non-self-adjoint and the corresponding eigenvalue problem is ruled by a non-
symmetric matrix and can exhibit complex eigenvalues. Langthjem and Sugiyama [25] and
Elishakoff [26] have made excellent surveys on the static and dynamic stabilities of systems loaded
with follower forces. Finite element analysis has been carried out to examine the nonlinear stability
of Beck’s columns [27-31]. It has been known since the time of Euler that flexible beams can
assume multiple equilibrium solutions under a given load. The existence and emergence of these
solutions has received much attention in the literature [32-36]. An equally interesting question
concerns the stability of these multiple configurations.
The post-buckling analysis of a uniform cantilever column is performed under a tip-
concentrated subtangential follower force. A relation is obtained for the applied load in terms of the
subtangential parameter and the tip-angle of the column. There is a limitation on the load rotation
parameter in obtaining solution of the equations arrived from the static stability criterion. The
limitation can be overcome adopting the dynamic stability criterion. The deformed configurations
of the column are obtained by solving directly the resulting non-linear differential equations
through fourth-order Runge-Kutta integration scheme. The range of load parameter is arrived at
which multiple equilibrium configurations of the column exist.
Figure 1. A uniform cantilever column under a tip-concentrated subtangential follower load
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48
2. Theoretical Formulation
The formulation of the problem is mainly based on an important relation of the flexural theory
(i.e.,ds
d
EI
M
1), the quantity
1 (the curvature of the deflected axis of the column)
characterizes the magnitude of bending deformation, which is proportional to bending moment, M
and inversely proportional to the product EI, called flexural rigidity of the column. Figure-1
represents a follower load P not always be tangent, but can be subtangential depending on a
parameter . Here 0 represents Euler’s column (unidirectional, vertical, tip-concentrated load
P) and 1 represents Beck’s column (tip-concentrated tangential load P). The differential
equation of the deflection curve is formulated here for the angle between the tangent to the bent
axis and the vertical, as a function of the length s of the curve measured from the tip of the column
as shown in Figure 1.
The moment-curvature relationship of a uniform cantilever column subjected to a tip-
concentrated subtangential follower load (P) is as follows [14, 17, and 18]
)()0(sin)()0(cos aa XXPYYPds
dEI
(1)
where
L
s
dsX )(cos)( (2)
L
s
dsY )(sin)( (3)
Here E is the Young’s modulus; I is the moment of inertia; L is the length of the column; is a
dummy variable; )0( is the tip-angle of the column; and is the subtangential parameter. At s
= 0, equations (2) and (3) give tip coordinates ( aa YX , ) of the column.
Differentiating equations (1) to (3) with respect to s, the following system of equations are
obtained:
0)0(sin2
2
Pds
dEI (4)
cosds
dX (5)
sinds
dY (6)
Boundary conditions for the differential equations (4) to (6) are:
At the tip of the column (s=0)
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49
0ds
d (7)
At the root of the column (s=L)
0 , X=0, Y=0 (8)
The solution of equations (4) to (8) is obtained in terms of elliptic integrals for one equilibrium
deformed configuration of the column [17, 18]. In this paper, a direct procedure is followed to
obtain many equilibrium solutions. The details of which are presented below.
Equations (4) to (8) form a two-point boundary value problem. DefiningEI
PL2
;
L
s ;
L
Xx ; and
L
Yy ; equations (4) to (8) are written in non-dimensional form as
0)0(sin2
2
d
d (9)
0cos d
dx (10)
0sin d
dy (11)
0
d
d at 0 (12)
0 yx at 1 (13)
Here
L
Y
L
Xyx aa
aa ,),( represents the tip-coordinates of the column in the non-dimensional
form.
Multiplying equation (9) by 2
d
d and integrating, one can obtain
)}0()1cos{()}0(cos{2
2
d
d (14)
This satisfies )0( at 0 . Now writing 22 sin21)0(cos k and
221)0()1(cos k , equation (14) is transformed to
)sin1( 22
2
k
d
d
(15)
The boundary conditions for equation (15) are:
nn
n
2)12(11sin
11
1
at 0 (16)
2
)0(sin
1sin 1
0
k at 1 (17)
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50
where
2
)0()1(sin
k . (18)
It should be noted that the condition (16) in Ref. [17] is for n =1(i.e., 1 =2
), which
corresponds to the first equilibrium configuration of the column. Integrating equations (15) to (17),
one can obtain a relation between the load parameter ( ) and the tip-angle ( )0( ) with
subtangential parameter ( ) as
2
22
1
0sin1
k
d (19)
By applying )0( 0 in equation (17) one can obtain a sequence of load parameters
1
),(n
n as
2
11
1sin
2121),(
nn
nfor
2
10 (20)
It should be noted that
1sin 1 does not exist for 1
2
1 and hence no static load is
possible to evaluate for the column [14, 17, 18]. In the sequence of load parameters, )1,( is the
linear critical load parameter for the specified subtangential parameter ( ). It is interesting to note
from equation (20) that the linear critical load parameter )1,( decreases with negative values of
. This is mainly due to the fact that the horizontal component of the force aids the bending of the
column. For2
10 , the horizontal component acts as a force opposing bending. As the
parameter increases upto the value of2
1 , the critical load parameter increases and finally at
2
1 attains the value 2 . Finite element analysis (FEA) results [27, 29, and 31] are found to be in
good agreement with the critical load parameter, )1,( given in equation (20). For2
1 , there is
no force able to maintain equilibrium of the column in its deflected position. To determine the
critical loads )1,( in this range, one has to follow the dynamic stability criterion in which straight
equilibrium configuration is the only equilibrium configuration [17]. Only one equilibrium
configuration is possible for the specified load parameter, )2,( . One can expect m ( 2 )
equilibrium configurations for the specified load parameter,
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51
)]1,(),,([ mm for 2
10 (21)
)]12,(),12,([ mm for 2
1 (22)
However for2
1 , multiple equilibrium configurations are possible for the specified load
parameter ( ). It should be noted that for 1k , equation (19) gives the load parameter,
2
00
11
tansec
tansecln
(23)
which is undefined for all the values of 1 in equation (16). Using 1k in equation (18) one can
find the tip-angle,
)1()0(
(24)
Figure 2. Variation of tip-angle, )0( with the subtangential parameter ( ) at which the load parameter ( )
is undefined.
The load parameter (λ) is undefined for the specified tip-angle, )0( of equation (24) and the
solution of the problem becomes singular. Figure-2 shows the variation of )0( with the applicable
range of the subtangential parameter ( ) at which the load parameter is undefined. For the
specified subtangential parameter ( ) and tip-angle ( )0( ), load parameter ( ) can be evaluated
from equation (19) through numerical integration. Gauss-Legendre quadrature scheme available in
MATLAB is utilized for evaluation of the integral in equation (19). For the tip-angle, )0( and the
corresponding load parameter ( ), equation (9) is written into two first-order differential equations
and integrated from 0 to 1 utilizing the fourth-order Runge-Kutta method and obtained the
unknown
d
d at 1 . Using the determined value of
d
d at =1 as well as other conditions in
0 0.1 0.2 0.3 0.4 0.5180
200
220
240
260
280
300
320
340
360
rotation parameter ()
tip
-an
gle
,
(0)
(deg
)
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52
equation (13): 0 yx at =1, the fourth-order non-linear differential equations (9) to (11)
were solved from 1 to 0 using the fourth-order Runge-Kutta method and obtained the
deformed configuration of the column. A uniform step size ( ) of 0.001 is considered to obtain
the numerical solution for the non-linear ordinary differential equations. The deformed shape of the
column including its tip-coordinates ( aa yx , ) are obtained at the end of the integration.
Replacing the constant angle ‘ ’ by ( 1 ) )0( in the mathematical formulation [37], one can
obtain resulting differential equation (4). By specifying the value of equivalent to )0( ( 1 ),
it is not possible to obtain the linear critical load parameter for the applicable range of the load
rotation parameter, <2
1. Because, specifying the tip-angle, )0( close to zero, the constant angle,
in Ref. [37], becomes zero for all the load rotation parameters ( ).
3. Numerical Results
Post-buckling behavior of a uniform cantilever column subjected to a tip-concentrated
subtangential load is examined. Many load parameters ( ) are obtained from equation (19) varying
n (= 1, 2, 3… etc.) for the specified tip-angle ( )0( ) and the subtangential parameter )2/1,0( .
Figure 3 and 4 show the variation of the load parameter ( ) with the tip-angle, )0( for the
subtangential parameter, β = 0.0 and 0.5. The asymptotic nature of the load parameter ( ) close to
the values of the tip-angle, )0( of Figure 2 can be seen clearly in Figures 3 and 4. Multiple
equilibrium solutions can be seen from these Figures 3 and 4 having different tip-angles ( )0( ) of
the cantilever column for a specified load parameter ( ) and the subtangential parameter ( ).
Figure 3. Variation of load parameter ( ) with tip-
angle, )0( of the cantilever column for the
subtangential parameter, β=0.0.
Figure 4. Variation of load parameter ( ) with tip-
angle, )0( of the cantilever column for the
subtangential parameter, β=0.5.
0 20 40 60 80 100 120 140 160 1800
50
100
150
200
250
300
tip-angle, (0)(deg)
loa
d p
ara
me
ter(
)
0 50 100 150 200 250 300 3500
50
100
150
200
250
300
tip-angle, (0)(deg)
loa
d p
ara
me
ter(
)
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53
Figures 5 to 8 show the deformed configurations of the column for the specified tip-angle,
060)0( and subtangential parameter, β=0.0, 0.1, 0.3 and 0.5, respectively. These figures are
drawn from the first, second and third equilibrium solutions having different values of the load
parameter ( ). The deformation pattern for a specified tip-angle )0( is found to differ due to
different value of the subtangential parameter, β.
Figure 5. Deformed configurations of the cantilever
column for β = 0.0 and 060)0(
Figure 6. Deformed configuration of the cantilever
column for β = 0.1 and 060)0(
Figure 7. Deformed configuration of the cantilever
column for β = 0.3 and 060)0(
Figure 8. Deformed configurations of the cantilever
column for β=0.5 and 060)0(
Figure 9 depicts the variation of along the length of the column for three load parameters
corresponding to β=0.0 and β=0.5, respectively for specified tip-angle, 060)0(
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
y
x
12 3
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
y
x
21
3
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
y
x
1
2
3
-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 10
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
y
x
2
31
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54
Figure 9. Variation of along the length of the column for the three load parameters
(a) 060)0( , 0.0 ; (b)
060)0( , 5.0
For the case of first equilibrium solution, )(s varies monotonically from zero to the tip-angle (
)0( ) whereas the second and third equilibrium solutions, the trend of )(s variation is different
and its magnitude does not exceeds the tip-angle, )0( . For higher load parameters having the same
tip-angle, (s) variation along the axis of the column is highly non-linear. In order to obtain the
deformed configuration of the column from equations (2) and (3), one has to store large amount of
(s)-data with increasing the load parameter, as evidenced from Figures 8. To overcome this type
of problem numerically the present approach is for direct integration of non-linear differential
equations providing the required initial conditions. The first equilibrium solutions are found to be in
good agreement with those of elliptic-function solution [17]. It may be noted that the increase in
load parameter give rise to the increase in the number of configurations.
Table 1. Comparison of load-deflection data for buckled column ( 0.0 ).
Finite element analysis [31] Present analytical
solution
)0( (deg) ax ay ax ay
2.5044 19.8 0.970 0.218 2.5046 0.9703 0.2173 2.6228 40.3 0.880 0.426 2.6270 0.8795 0.4251 2.8424 59.8 0.744 0.591 2.8390 0.7426 0.5917 3.1903 79.5 0.564 0.716 3.1817 0.5643 0.7170 3.7455 99.4 0.356 0.789 3.7258 0.3556 0.7902 4.6486 119.2 0.132 0.802 4.6044 0.1323 0.8039 6.2697 139.5 0.101 0.751 6.2172 -0.1012 0.7525 9.9411 159.3 0.330 0.628 9.7359 -0.3318 0.6306
Table 1 gives a comparison of the finite element analysis (FEA) results [31] with the present
analytical results for =0. It should be noted that the tip-angle, )0( and tip-deflections are
obtained from FEA by specifying the load parameter ( ) and the subtangential parameter ( ). In
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-60
-40
-20
0
20
40
60
(= s/L)
(
deg
)
=2.841754
=25.575788
=71.043856
a)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10
10
20
30
40
50
60
(= s/L)
(
deg
)
=10.216231
=91.946082
=255.405785
b)
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55
the present analytical solution, the obtained tip-angle, )0( of FEA is considered for estimating the
load parameter ( ) and obtaining the deformed configuration of the column.
Table 2. Comparison of load-deflection data for the specified subtangential parameter, and tip-angle, )0( upto
600
Finite element analysis [31] Present analytical solution
)0( (deg) ax ay ax ay
1.0
2.8745 20.8 0.968 0.227 2.8669 0.9676 0.2262
3.2644 60.9 0.735 0.597 3.1733 0.7369 0.5949
2.0
3.3778 18.9 0.973 0.204 3.3529 0.9736 0.2037
3.8442 59.9 0.748 0.582 3.6203 0.7492 0.5807
3.0
4.1206 18.9 0.973 0.204 4.0804 0.9742 0.2002
4.7029 59.6 0.757 0.571 4.3180 0.7576 0.5684
5.3814 21.8 0.966 0.223 5.3245 0.9672 0.2227
6.1734 59.7 0.766 0.553 5.5402 0.7673 0.5511
497.0
9.0899 19.3 0.976 0.178 8.9536 0.9799 0.1435
10.6074 60.1 0.797 0.490 9.2348 0.8154 0.4022
FEA results in Table 2 for the specified subtangential parameter ( ) and the tip-angle, )0(
upto 600 are comparable with those obtained from the present analytical solutions. The discrepancy
in the FEA results may be in the formulation of the nonlinear problem or in the FE models (which
may need more refinement) of Ref. [31].
Tables 3 to 8 provide the load-deflection data of the buckled cantilever columns for the
specified subtangential parameter ( ). The elliptic integral solutions of Timoshenko and Gere [10]
for =0 and those of Ref. [17] for =0.1 to 0.5 are found to be in good agreement with the
present first equilibrium solutions in Tables 3 to 8. Results of the present analysis will be useful to
validate the geometric non-linear finite element solutions of cantilever columns.
Mutyalarao et al. [38] have examined the dynamic stability of cantilever columns under a tip-
concentrated subtangential follower force. A simple numerical iterative scheme is presented to
obtain the critical and post-critical loads of the columns for the specified tip-angle ( )0( ) and the
load rotation parameter ( ). The critical load parameter ( cr ) for the load rotation parameter ( )
was obtained by specifying the tip-angle, )0( =0.010. The critical load parameter ( cr ) is found to
vary with the load rotation parameter ( ). The critical load parameters obtained from the first two
4.0
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56
eigencurves (i.e., load versus frequency curves) [38] are found to be in excellent agreement with the
present analysis results (i.e., )1,( and )2,( for2
1 ).
Table 3. Load-deflection data of the buckled cantilever columns ( 0.0 ).
tip-angle, )0( (deg) First equilibrium Second equilibrium Third equilibrium
ax ay ax ay ax ay
(0) 0 2.4674 1.0000 0.0000 22.2066 1.0000 0.0000 61.6850 1.0000 0.0000
10 2.4768 0.9924 0.1108 22.2914 0.9924 -
0.0369
61.9205 0.9924 0.0221
20 2.5054 0.9697 0.2194 22.5485 0.9697 -
0.0731
62.6348 0.9698 0.0439
30 2.5541 0.9324 0.3239 22.9865 0.9324 -
0.1080
63.8514 0.9326 0.0647
40 2.6245 0.8812 0.4222 23.6204 0.8812 -
0.1407
65.6121 0.8815 0.0844
50 2.7192 0.8170 0.5126 24.4727 0.8170 -
0.1708
67.9796 0.8176 0.1025
60 2.8418 0.7410 0.5932 25.5758 0.7411 -
0.1977
71.0439 0.7419 0.1187
70 2.9972 0.6546 0.6626 26.9749 0.6547 -
0.2208
74.9302 0.6560 0.1327
80 3.1925 0.5594 0.7195 28.7329 0.5595 -
0.2398
79.8136 0.5613 0.1441
90 3.4376 0.4569 0.7628 30.9383 0.4571 -
0.2542
85.9398 0.4596 0.1528
100 3.7465 0.3490 0.7915 33.7183 0.3493 -
0.2638
93.6619 0.3538 0.1586
110 4.1401 0.2372 0.8052 37.2606 0.2376 -
0.2683
103.5017 0.2390 0.1610
120 4.6506 0.1232 0.8032 41.8550 0.1239 -
0.2675
116.2640 0.1306 0.1605
130 5.3305 0.0082 0.7851 47.9745 0.0095 -
0.2614
133.2624 0.0085 0.1554
140 6.2728 -
0.1069
0.7504 56.4549 -
0.1042
-
0.2494
156.8193 -
0.1101
0.1483
150 7.6622 -
0.2223
0.6979 68.9596 -
0.2181
-
0.2316
191.5543 -
0.2266
0.1381
160 9.9438 -
0.3403
0.6246 89.4945 -
0.3427
-
0.2088
248.5960 -
0.3300
0.1219
170 14.682
2
-
0.4714
0.5200 132.140
2
-
0.4679
-
0.1743
367.0562 -
0.5092
0.0862
Table 4. Load-deflection data of the buckled cantilever columns ( 1.0 )
tip-angle, )0( (deg) First equilibrium Second equilibrium Third equilibrium
ax ay ax ay ax ay
(0) 0
2.8296 1.0000 0.0000 21.1696 1.0000 0.0000 63.4464 1.0000 0.0000
10 2.8381 0.9925 0.1099 21.2356 0.9941 -
0.0165
63.6416 0.9934 0.0369
20 2.8640 0.9701 0.2177 21.4352 0.9766 -
0.0331
64.2323 0.9739 0.0728
30 2.9079 0.9332 0.3213 21.7739 0.9477 -
0.0499
65.2343 0.9417 0.1068
40 2.9710 0.8825 0.4188 22.2610 0.9079 -
0.0670
66.6749 0.8975 0.1381
50 3.0550 0.8191 0.5084 22.9105 0.8578 -
0.0844
68.5948 0.8420 0.1658
60 3.1624 0.7442 0.5882 23.7418 0.7981 -
0.1022
71.0509 0.7761 0.1892
70 3.2964 0.6592 0.6568 24.7816 0.7297 -
0.1204
74.1206 0.7010 0.2076
80 3.4617 0.5656 0.7130 26.0656 0.6536 -
0.1390
77.9080 0.6182 0.2206
90 3.6640 0.4652 0.7557 27.6421 0.5710 -
0.1578
82.5537 0.5288 0.2278
100 3.9117 0.3599 0.7840 29.5772 0.4829 -
0.1768
88.2491 0.4339 0.2287
110 4.2160 0.2515 0.7974 31.9625 0.3906 -
0.1959
95.2595 0.3363 0.2236
120 4.5928 0.1419 0.7956 34.9280 0.2951 -
0.2147
103.9612 0.2322 0.2102
130 5.0654 0.0327 0.7783 38.6655 0.1977 -
0.2332
114.9068 0.1319 0.1918
140 5.6696 -
0.0743
0.7455 43.4689 0.0993 -
0.2510
128.9428 0.0266 0.1653
150 6.4631 -
0.1779
0.6973 49.8171 0.0006 -
0.2679
147.4436 -
0.0779
0.1334
160 7.5469 -
0.2771
0.6331 58.5549 -
0.0979
-
0.2833
172.8289 -
0.1748
0.0995
170 9.1209 -
0.3718
0.5519 71.3614 -
0.1976
-
0.2977
209.8940 -
0.2737
0.0536
180 11.6623 -
0.4635
0.4499 92.2790 -
0.3101
-
0.3147
270.1496 -
0.3755
0.0034
190 16.8353 -
0.5595
0.3143 135.5107 -
0.4144
-
0.3279
393.9067 -
0.5204
-
0.0745
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
57
Table 5. Load-deflection data of the buckled cantilever columns ( 2.0 )
tip-angle, )0( (deg) First equilibrium Second equilibrium Third equilibrium
ax ay ax ay ax ay
(0) 0
3.3251 1.0000 0.0000 19.8890 1.0000 0.0000 65.7180 1.0000 0.0000
10 3.3328 0.9926 0.1087 19.9384 0.9953 0.0045 65.8768 0.9941 0.0514
20 3.3563 0.9705 0.2153 20.0878 0.9813 0.0084 66.3566 0.9765 0.1014
30 3.3958 0.9342 0.3178 20.3402 0.9583 0.0110 67.1672 0.9476 0.1489
40 3.4523 0.8844 0.4141 20.7013 0.9265 0.0118 68.3261 0.9078 0.1927
50 3.5270 0.8220 0.5026 21.1791 0.8865 0.0104 69.8583 0.8579 0.2316
60 3.6214 0.7484 0.5814 21.7848 0.8389 0.0061 71.7987 0.7989 0.2646
70 3.7377 0.6650 0.6492 22.5333 0.7843 -
0.0013
74.1933 0.7317 0.2909
80 3.8788 0.5734 0.7046 23.4439 0.7237 -
0.0122
77.1025 0.6576 0.3097
90 4.0482 0.4755 0.7467 24.5420 0.6578 -
0.0268
80.6046 0.5778 0.3205
100 4.2507 0.3730 0.7746 25.8608 0.5876 -
0.0451
84.8020 0.4935 0.3228
110 4.4925 0.2680 0.7880 27.4441 0.5141 -
0.0673
89.8292 0.4063 0.3163
120 4.7819 0.1623 0.7866 29.3502 0.4382 -
0.0932
95.8652 0.3171 0.3006
130 5.1298 0.0581 0.7703 31.6589 0.3608 -
0.1226
103.153
1
0.2275 0.2762
140 5.5516 -
0.0430
0.7395 34.4811 0.2829 -
0.1554
112.030
2
0.1398 0.2431
150 6.0691 -
0.1391
0.6944 37.9766 0.2053 -
0.1911
122.979
5
0.0588 0.2036
160 6.7144 -
0.2287
0.6357 42.3839 0.1287 -
0.2294
136.719
8
-
0.0283
0.1529
170 7.5376 -
0.3103
0.5638 48.0789 0.0535 -
0.2699
154.376
6
-
0.1096
0.0968
180 8.6221 -
0.3830
0.4790 55.6955 -
0.0198
-
0.3123
177.838
6
-
0.1838
0.0341
190 10.120
7
-
0.4460
0.3808 66.4125 -
0.0925
-
0.3577
210.597
9
-
0.2507
-
0.0388 200 12.358
8
-
0.4990
0.2671 82.7742 -
0.1683
-
0.4068
260.146
2
-
0.2982
-
0.1103 210 16.233
1
-
0.5431
0.1308 111.902
3
-
0.2203
-
0.4471
347.317
6
-
0.3709
-
0.2013 220 26.386
1
-
0.5844
-
0.0622
191.383
1
-
0.4778
-
0.5200
581.176
9
-
0.4465
-
0.3170
Table 6. Load-deflection data of the buckled cantilever columns ( 3.0 )
tip-angle, )0( (deg) First equilibrium Second equilibrium Third equilibrium
ax ay ax ay ax ay
(0) 0
4.0550 1.0000 0.0000 18.2284 1.0000 0.0000 68.8384 1.0000 0.0000
10 4.0621 0.9928 0.1068 18.2635 0.9959 0.0263 68.9650 0.9944 0.0654
20 4.0835 0.9712 0.2116 18.3694 0.9838 0.0518 69.3468 0.9777 0.1293
30 4.1195 0.9357 0.3123 18.5477 0.9637 0.0753 69.9898 0.9502 0.1903
40 4.1706 0.8871 0.4070 18.8015 0.9362 0.0961 70.9044 0.9126 0.2469
50 4.2377 0.8263 0.4939 19.1352 0.9017 0.1134 72.1054 0.8655 0.2979
60 4.3217 0.7546 0.5713 19.5546 0.8608 0.1264 73.6131 0.8098 0.3421
70 4.4242 0.6734 0.6379 20.0675 0.8143 0.1344 75.4539 0.7468 0.3784
80 4.5468 0.5845 0.6924 20.6836 0.7629 0.1371 77.6612 0.6776 0.4061
90 4.6917 0.4895 0.7338 21.4154 0.7076 0.1338 80.2773 0.6035 0.4244
100 4.8618 0.3904 0.7615 22.2787 0.6494 0.1245 83.3557 0.5259 0.4330
110 5.0605 0.2892 0.7751 23.2933 0.5892 0.1089 86.9633 0.4463 0.4314
120 5.2921 0.1879 0.7743 24.4846 0.5280 0.0871 91.1851 0.3661 0.4198
130 5.5622 0.0884 0.7594 25.8850 0.4668 0.0592 96.1298 0.2861 0.3968
140 5.8778 -
0.0073
0.7307 27.5369 0.4065 0.0254 101.9377 0.2092 0.3655
150 6.2484 -
0.0974
0.6889 29.4961 0.3480 -
0.0139
108.7930 0.1360 0.3241
160 6.6861 -
0.1802
0.6349 31.8379 0.2921 -
0.0583
116.9424 0.0682 0.2738
170 7.2076 -
0.2542
0.5696 34.6662 0.2395 -
0.1071
126.7242 0.0083 0.2181
180 7.8363 -
0.3181
0.4941 38.1289 0.1908 -
0.1598
138.6162 -
0.0501
0.1507
190 8.6061 -
0.3706
0.4097 42.4448 0.1465 -
0.2158
153.3191 -
0.0988
0.0771
200 9.5687 -
0.4108
0.3173 47.9538 0.1069 -
0.2746
171.9122 -
0.1392
0.0060
210 10.8078 -
0.4379
0.2179 55.2194 0.0723 -
0.3355
196.1686 -
0.1688
-
0.0764 220 12.4723 -
0.4512
0.1116 65.2645 0.0424 -
0.3994
229.2764 -
0.1855
-
0.1604 230 14.8645 -
0.4497
-
0.0026
80.2149 0.0145 -
0.4677
277.7944 -
0.1833
-
0.2434 240 18.7530 -
0.4319
-
0.1299
105.6158 0.0049 -
0.5267
358.6438 -
0.1988
-
0.3560 250 27.3317 -
0.3925
-
0.2910
165.1976 -
0.0354
-
0.6373
543.3032 -
0.2388
-
0.5508
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
58
Table 7. Load-deflection data of the buckled cantilever columns ( 4.0 ).
tip-angle, )0( (deg) First equilibrium Second equilibrium Third equilibrium
ax ay ax ay ax ay
(0) 0
5.2924 1.0000 0.0000 15.8616 1.0000 0.0000 73.6801 1.0000 0.0000 10 5.2991 0.9931 0.1034 15.8843 0.9959 0.0500 73.7792 0.9944 0.0786 20 5.3194 0.9724 0.2048 15.9525 0.9835 0.0989 74.0778 0.9776 0.1556 30 5.3535 0.9384 0.3023 16.0673 0.9632 0.1454 74.5792 0.9500 0.2295 40 5.4017 0.8918 0.3940 16.2299 0.9354 0.1885 75.2893 0.9122 0.2985 50 5.4646 0.8337 0.4782 16.4424 0.9007 0.2271 76.2165 0.8651 0.3616 60 5.5428 0.7651 0.5532 16.7077 0.8598 0.2604 77.3720 0.8095 0.4172 70 5.6374 0.6876 0.6178 17.0290 0.8136 0.2875 78.7700 0.7468 0.4644 80 5.7493 0.6028 0.6708 17.4110 0.7631 0.3078 80.4284 0.6782 0.5022 90 5.8801 0.5124 0.7114 17.8589 0.7092 0.3207 82.3692 0.6051 0.5300
100 6.0313 0.4183 0.7388 18.3795 0.6532 0.3260 84.6192 0.5291 0.5472 110 6.2050 0.3225 0.7527 18.9809 0.5961 0.3234 87.2111 0.4517 0.5536 120 6.4037 0.2268 0.7531 19.6731 0.5392 0.3129 90.1845 0.3745 0.5491 130 6.6304 0.1333 0.7403 20.4683 0.4836 0.2947 93.5881 0.2993 0.5343 140 6.8886 0.0438 0.7146 21.3816 0.4303 0.2691 97.4812 0.2260 0.5073 150 7.1829 -
0.0400
0.6769 22.4317 0.3804 0.2366 101.9371 0.1585 0.4725 160 7.5187 -
0.1164
0.6282 23.6421 0.3349 0.1978 107.0470 0.0974 0.4292 170 7.9028 -
0.1840
0.5696 25.0426 0.2946 0.1534 112.9258 0.0421 0.3754 180 8.3440 -
0.2414
0.5025 26.6718 0.2602 0.1043 119.7199 -
0.0041
0.3161 190 8.8532 -
0.2877
0.4285 28.5798 0.2324 0.0513 127.6191 -
0.0396
0.2522 200 9.4449 -
0.3220
0.3491 30.8337 0.2115 -
0.0046
136.8740 -
0.0683
0.1808 210 10.1384 -
0.3436
0.2660 33.5254 0.1978 -
0.0624
147.8238 -
0.0840
0.1122 220 10.9602 -
0.3523
0.1808 36.7843 0.1916 -
0.1211
160.9405 -
0.0919
0.0353 230 11.9477 -
0.3479
0.0951 40.7995 0.1928 -
0.1800
176.9046 -
0.0898
-
0.0365 240 13.1568 -
0.3302
0.0104 45.8606 0.2015 -
0.2380
196.7430 -
0.0767
-
0.1051 250 14.6750 -
0.2992
-
0.0721
52.4387 0.2175 -
0.2944
222.1009 -
0.0526
-
0.1800 260 16.6515 -
0.2550
-
0.1516
61.3660 0.2411 -
0.3482
255.8370 -
0.0120
-
0.2440 270 19.3722 -
0.1967
-
0.2281
74.3014 0.2743 -
0.3989
303.5468 0.0379 -
0.3127 280 23.4987 -
0.1222
-
0.3033
95.2552 0.3218 -
0.4307
378.4959 0.0974 -
0.3817 290 31.2565 -
0.0232
-
0.3853
138.3885 0.3603 -
0.5184
526.4898 0.1646 -
0.4963
Table 8. Load-deflection data of the buckled cantilever columns ( 5.0 )
tip-angle, )0( (deg) First equilibrium Second equilibrium Third equilibrium
ax ay ax ay ax ay
(0) 0
9.8696 1.0000 0.0000 88.8264 1.0000 0.0000 246.7401 1.0000 0.0000 10 9.8790 0.9943 0.0870 88.9110 0.9943 0.0870 246.9752 0.9943 0.0870 20 9.9073 0.9773 0.1723 89.1656 0.9774 0.1723 247.6822 0.9774 0.1723 30 9.9547 0.9494 0.2544 89.5921 0.9495 0.2544 248.8669 0.9495 0.2544 40 10.021
6
0.9112 0.3317 90.1941 0.9114 0.3317 250.5391 0.9114 0.3317 50 10.108
5
0.8636 0.4027 90.9766 0.8638 0.4027 252.7127 0.8639 0.4027 60 10.216
2
0.8075 0.4662 91.9461 0.8078 0.4663 255.4058 0.8079 0.4663 70 10.345
7
0.7442 0.5211 93.1110 0.7446 0.5212 258.6416 0.7447 0.5213 80 10.497
9
0.6750 0.5664 94.4814 0.6756 0.5667 262.4484 0.6757 0.5668 90 10.674
4
0.6015 0.6015 96.0698 0.6022 0.6019 266.8604 0.6024 0.6022 100 10.876
7
0.5252 0.6259 97.8907 0.5259 0.6265 271.9185 0.5262 0.6268 110 11.106
8
0.4476 0.6393 99.9616 0.4485 0.6402 277.6711 0.4488 0.6407 120 11.367
0
0.3705 0.6417 102.303
2
0.3715 0.6431 284.1754 0.3719 0.6437 130 11.660
0
0.2954 0.6335 104.939
6
0.2966 0.6353 291.4989 0.2969 0.6363 140 11.988
8
0.2239 0.6152 107.899
6
0.2245 0.6164 299.7210 0.2249 0.6176 150 12.357
4
0.1574 0.5873 111.216
9
0.1579 0.5889 308.9357 0.1581 0.5898 160 12.770
2
0.0971 0.5509 114.931
6
0.0973 0.5529 319.2544 0.0978 0.5541 170 13.232
4
0.0444 0.5070 119.091
4
0.0443 0.5095 330.8095 0.0449 0.5103 180 13.750
4
0.0000 0.4570 123.753
3
-
0.0001
0.4588 343.7593 0.0001 0.4624 190 14.331
8
-
0.0352
0.4020 128.986
1
-
0.0353
0.4058 358.2948 -
0.0348
0.4057 200 14.985
9
-
0.0606
0.3437 134.873
1
-
0.0615
0.3457 374.6474 -
0.0610
0.3465 210 15.724
0
-
0.0760
0.2835 141.516
3
-
0.0771
0.2855 393.1010 -
0.0788
0.2901 220 16.560
3
-
0.0811
0.2229 149.042
4
-
0.0824
0.2271 414.0066 -
0.0829
0.2217 230 17.512
2
-
0.0762
0.1635 157.609
8
-
0.0772
0.1689 437.8049 -
0.0769
0.1650 240 18.602
2
-
0.0616
0.1067 167.420
2
-
0.0626
0.1065 465.0560 -
0.0626
0.1092 250 19.859
4
-
0.0377
0.0539 178.734
6
-
0.0378
0.0553 496.4850 -
0.0378
0.0531 260 21.322
0
-
0.0053
0.0063 191.897
9
-
0.0027
0.0054 533.0497 -
0.0039
0.0040 270 23.041
8
0.0348 -
0.0349
207.376
3
0.0323 -
0.0348
576.0453 0.0343 -
0.0356 280 25.091
1
0.0818 -
0.0687
225.819
8
0.0780 -
0.0671
627.2771 0.0775 -
0.0667 290 27.574
1
0.1346 -
0.0943
248.167
0
0.1326 -
0.0954
689.3528 0.1326 -
0.0869 300 30.648
7
0.1923 -
0.1111
275.838
3
0.1860 -
0.1092
766.2174 0.1911 -
0.1099 310 34.568
4
0.2540 -
0.1186
311.115
3
0.2481 -
0.1161
864.2092 0.2510 -
0.1183 320 39.775
4
0.3193 -
0.1165
357.978
2
0.3163 -
0.1211
994.3839 0.3169 -
0.1123 330 47.138
8
0.3883 -
0.1046
424.249
6
0.3900 -
0.1022
1178.4712 0.3905 -
0.1069 340 58.729
0
0.4628 -
0.0829
528.560
9
0.4641 -
0.0866
1468.2247 0.4645 -
0.0834 350 81.729
7
0.5507 -
0.0595
735.567
1
0.6835 -
0.1072
2043.2418 0.5488 -
0.0283
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
59
Concluding Remarks
Every nonlinear problem must be treated as a self-respecting entity and to be solved on its own
merit. This may be the reason why the literature shows several investigations on the nonlinear
problem of cantilever columns loaded by a subtangential follower force for the past seven decades.
Rao and Rao [14-23] have published extensively in this area in the late 1980s and early 1990s;
recently by the current authors [36-38]; and other researchers [46-50]. Many of these articles were
not discussed about the existence of multiple solutions for the nonlinear differential equations while
studying the post-buckling behavior of cantilever columns.
A simple numerical procedure is followed in this article to obtain the deformed configuration of
the column when it is subjected to a tip-concentrated subtangential follower load. Equation (20)
clearly indicates the limits on the subtangential parameter ( ) to apply static stability criterion for
buckling and post-buckling analysis of cantilever columns. Multiple equilibrium solutions are
found from the generated load versus tip-angle curves having different tip-angles ( )0( ) for the
specified load parameter (λ), which indicates non-uniqueness in the solution of the problem [51].
The present boundary value problem can also be solved using a symbolic computer algebra code
like Mathematica.
Future work is planned to analyze several test configurations (viz., tangentially loaded column,
cantilever column mounting solid rocket motor at free-end, free-free column under an end thrust
and post-buckling of simply supported stepped column) for investigating the buckling and post-
buckling behavior of columns. Other challenging tasks identified are the dynamic stability
characteristics of tapered truncated cantilever wedges and cones, deformations of beams/columns
considering both geometric and material nonlinearities and optimum design of beam/column
configurations for the specified load and allowable limits.
References
[1] Antman S.S.: Nonlinear Problems of Elasticity. Springer-Verlag, Berlin (1995).
[2] Love A.E.H.: A Treatise on the Mathematical Theory of Elasticity. Dover Publication, New York (1944).
[3] Barten H.J.: On the deflection of a cantilever beam. Quarterly of Applied Mathematics, 2, 168-171
(1944).
[4] Bisshopp K.E., Drucker D.C.: Large deflection of cantilever beams. Quarterly of Applied Mathematics,
3, 272-275 (1945).
[5] Barten H.J.: On the deflection of a cantilever beam. Quarterly of Applied Mathematics, 3, 275-276
(1945).
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
60
[6] Lau J.H.: Large deflection of cantilever beam. Journal of the Engineering Mechanics, American Society
of Civil Engineers (ASCE), 107, 259-264 (1981).
[7] Lau J.H.: Large deflections of beams with combined loads. Journal of the Engineering Mechanics
Division, ASCE, 108, 180-185 (1982).
[8] Landau L.D., Lifshitz E.M.: Theory of Elasticity. Pergamon Press, New York (1986).
[9] Nageswara Rao B., Venkateswara Rao G.: On the large deflection of cantilever beams with end rotational
load. Journal of Applied Mathematics and Mechanics (ZAMM), 66, 507-509 (1986).
DOI: 10.1002/zamm.19860661027
[10] Timoshenko S.P., Gere J.M.: Theory of Elastic Stability. McGraw-Hill, New York (1961)
[11] Chen L.: An integral approach for large deflection cantilever beams. International Journal of Non-
Linear Mechanics, 45, 301-305 (2010)
DOI:10.1016/j.ijnonlinmec.2009.12.004
[12] Bolotin V.V.: Nonconservative Problems of the Theory of Elastic Stability. Pergamon Press, New York
(1963).
[13] Ziegler H.: Principles of Structural Stability. Blaisdell Publication Co., Toronto (1968).
[14] Nageswara Rao B., Venkateswara Rao G.: Applicability of static or dynamic criterion for the stability of
a cantilever column under a tip-concentrated subtangential follower force. Journal of Sound and
Vibration, 120, 197-200 (1987).
DOI: 10.1016/0022-460X(88)90345-8
[15] Nageswara Rao B., Venkateswara Rao G.: Stability of a cantilever column under a tip-concentrated
subtangential follower force with the value of subtangential parameter closed to or equal to ½. Journal of
Sound and Vibration, 125, 181-184 (1988).
[16] Nageswara Rao B., Venkateswara Rao G.: Post-critical behaviour of a uniform cantilever column under
a tip-concentrated follower force. Journal of Sound and Vibration, 132, 350-352 (1989).
DOI: 10.1007/BF02561170
[17] Nageswara Rao B., Venkateswara Rao G.: Post buckling analysis of a uniform cantilever column
subjected to tip concentrated subtangential follower force. Forschung im Ingenieurwesen, 55, 36-38
(1989).
DOI: 10.1007/BF02559021
[18] Nageswara Rao B., Venkateswara Rao G.: Some studies on buckling and post-buckling of cantilever
columns subjected to conservative or nonconservative loads. Journal of the Aeronautical Society of
India, 41, 165-181 (1989).
[19] Nageswara Rao B., Venkateswara Rao G.: Stability of a cantilever column under a tip-concentrated
subtangential follower force with damping. Journal of Sound and Vibration, 138, 341-344 (1990).
[20] Nageswara Rao B., Venkateswara Rao G.: Stability of tapered cantilever columns subjected to a tip-
concentrated subtangential follower force. Forschung im Ingenieurwesen, 56, 93-96 (1990).
DOI: 10.1007/BF02560974
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
61
[21] Nageswara Rao B., Venkateswara Rao G.: Post-critical behaviour of a tapered cantilever column
subjected to a tip-concentrated follower force. Journal of Applied Mathematics and Mechanics (ZAMM),
71, 471-473 (1991).
DOI: 10.1002/zamm.19910711116
[22] Nageswara Rao B., Venkateswara Rao G.: Stability of tapered cantilever columns subjected to a tip-
concentrated follower force with or without damping. Computers & Structures, 37, 333-342 (1990).
DOI: 10.1016/0045-7949(90)90325-V
[23] Nageswara Rao B., Venkateswara Rao G.: Post-critical behaviour of a uniform cantilever column
subjected to a tip-concentrated subtangential follower force with small damping. Forschung im
Ingenieurwesen, 57, 81-86 (1991).
DOI: 10.1007/BF02561170
[24] Zakharov Y.V., Okhotkin K.G., Skorobogatov A.D.: Bending of bars under a follower load. Journal of
Applied Mechanics and Technical Physics, 45, 756-763 (2004).
DOI: 10.1023/B:JAMT.0000037975.91152.01
[25] Langthjem M.A., Sugiyama Y.: Dynamic stability of columns subjected to follower loads: a survey.
Journal of Sound and Vibration, 238, 809-851 (2000).
DOI: 10.1006/jsvi.2000.3137
[26] Elishakoff I.: Controversy associated with the so-called ‘Follower Forces’: critical overview. Applied
Mechanics Reviews, 58, 117-142 (2005).
DOI: 10.1115/1.1849170
[27] Kikuchi F.: A finite element method for non-self adjoint problems. International Journal of Numerical
Methods in Engineering, 6, 39-54 (1973).
DOI: 10.1002/nme.1620060106
[28] Vitaliani R.V., Gasparini A.M., Saetta A.V.: Finite element solution of the stability problem for
nonlinear undamped and damped systems under nonconservative loading. International Journal of Solids
and Structures, 34, 2497-2516 (1997).
DOI: 10.1016/S0020-7683(96)00115-1
[29] Langthjem M.A., Sugiyama Y.: Optimum design of cantilevered columns under the combined action of
conservative and nonconservative loads. Part I. The undamped case. Computers & Structures, 74, 385–
398 (2000).
DOI: 10.1016/S0045-7949(99)00050-4
[30] Anderson S.B., Thomsen J.J.: Post-critical behaviour of Beck’s column with a tip mass. International
Journal of Nonlinear Mechanics, 37, 135-151 (2002).
DOI: 10.1016/S0020-7462(00)00102-5
[31] Kwasniewski L.: Numerical verification of post-critical Beck’s column behavior. International Journal
of Non-Linear Mechanics, 45, 242-255 (2010).
DOI: 10.1016/j.ijnonlinmec.2009.11.007
[32] Navaee S., Elling R.E.: Equillibrium configurations of cantilever beams subjected to inclined end loads.
Journal of Applied Mechanics, Transactions of the American Society of Mechanical Engineers (ASME),
59, 572 – 579 (1992).
DOI: 10.1115/1.2893762
[33] Navaee S., Elling R.E.: Possible ranges of end slope for cantilever beams. Journal of Engineering
Mechanics, American Society of Civil Engineering (ASCE), 119, 630-635 (1993).
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
62
DOI: 10.1061/(ASCE)0733-9399(1993)119:3(630)
[34] Raboud D.W., Lipsett A.W., Faulkner M.G.: Stability evaluation of very flexible cantilever beams.
International Journal of Non-Linear Mechanics, 36, 1109 – 1122 (2001).
DOI: 10.1016/S0020-7462(00)00075-5
[35] Batista M., Kosel F.: Cantilever beam equilibrium configurations. International Journal of Solids &
Structures, 42, 4663-4672 (2005).
DOI: 10.1016/j.ijsolstr.2005.02.008
[36] Mutyalarao M., Bharathi D., Nageswara Rao B.: On the uniqueness of large deflections of a uniform
cantilever beam under a tip-concentrated rotational load. International Journal of Non-Linear Mechanics,
45, 433-441 (2010).
DOI: 10.1016/j.ijnonlinmec.2009.12.015
[37] Mutyalarao M., Bharathi D., Nageswara Rao B.: Large deflections of a cantilever beam under an
inclined end load. Applied Mathematics and Computation, 217, 3607-3613, (2010).
DOI: 10.1016/j.amc.2010.09.021
[38] Mutyalarao M., Bharathi D., Nageswara Rao B.: Dynamic stability of cantilever columns under a tip-
concentrated subtangential follower force. Mathematics and Mechanics of Solids,18 (5), 449-463 (2013)
DOI: 10.1177/108128651244236
[39] Willems N.: Experimental verificationof the dynamic stability of a tangentially loaded cantilever
column. Journal of Applied Mechanics, Transactions of the American Society of Mechanical Engineers
(ASME), 33, 460-461 (1966).
[40] Huang N.C., Nachbar W., Nemat-Nasser S.: On Willems’ experimental verification of the critical load
in Beck’s problem. Journal of Applied Mechanics, Transactions of the American Society of Mechanical
Engineers (ASME), 34, 243-245 (1967).
[41] Sugiyama Y., Katayama K., Kiriyama K.: Experimetal verification of dynamid stability of vertical
cantilever columns subjected to a sub-tangential force. Journal of Sound and Vibration, 236 (2), 193-207
(2000).
DOI: 10.1006/jsvi.1999.2969
[42] Beal T.R.: Dynamic stability of a flexible missile under constant and pulsating thrusts. American
Institute of aeronautics and Astronautics (AIAA) Journal, 3, 486-494 (1965).
[43] Feodos’ev V.I.: On a stability problem. Journal of Applied Mathematics and Mechanics (PMM), 29,
445-446 (1965).
[44] Guran A., Ossia K.: On the stability of a flexible missile under an end thrust. Mathematical and
Computer Modelling, 14, 965-968 (1990).
DOI: 10.1016/0895-7177(90)90322-E
[45] Babcock C.D., Waas A.M.: Effect of stress concentrations in composite structures. National Aeronautics
and Space Administration, NASA CR 176410 (1985).
[46] Nair R.G., Rao G.V., Singh G.: Stability of a short uniform cantilever column subjected to an
intermediate follower force. Journal of Sound and Vibration, 253, 1125-1130 (2002).
DOI: 10.1006/jsvi.2001.4079
[47] Shvartsman B.S.: Large deflections of a cantilever beam subjected to a follower force.
Journal of Sound and Vibration, 304, 969-973 (2007).
M. Mutyalarao et al. - Can. J. Basic Appl. Sci. Vol. 02(02), 46-63, 2014
63
DOI: 10.1016/j.jsv.2007.03.010
[48] Djondjorov P.A., Vassilev V.M.: On the dynamic stability of a cantilever under tangential follower
force according to Timoshenko beam theory. Journal of Sound and Vibration, 311, 1431-1437 (2008).
DOI: 10.1016/j.jsv.2007.10.005
[49] Shvartsman B.S.: Direct method for analysis of flexible cantilever beam subjected to two follower
forces. International Journal of Non-Linear Mechanics, 44, 249-252 (2009).
DOI: 10.1016/j.ijnonlinmec.2008.11.004
[50] Ashok Kumar N., Lakshmana Rao C., Srinivasan S.M.: Large deflection of constant curvature
cantilever beam under follower load. International Journal of Mechanical Sciences, 52, 440-445 (2010).
DOI: 10.1016/j.ijmecsci.2009.11.004
[51] Mutyalarao M: Uniqueness of the solution for non-linear differential equations of beams subjected to
inclined end loads. Ph. D Thesis, Department of Engineering Mathematics, College of Engineering,
Andhra University, Visakhapatnam, India (2012).