information and pool sap2000 manuals english problem 2 012

8/12/2019 Information and Pool Sap2000 Manuals English Problem 2 012

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COMPUTERS &

STRUCTURES

INC.

R Software Verification

PROGRAM NAME: SAP2000

REVISION NO.: 0

EXAMPLE 2-012 - 1

EXAMPLE 2-012

SHELL PLATE BENDING WHEN SHEAR DEFORMATIONS ARE SIGNIFICANT

PROBLEM DESCRIPTION

This example is the example shown on page 376 in Roark and Young 1975. It is

an annular plate with an inner radius of 1.4 inches, an outer radius of 2 inches

and a thickness of 0.5 inch. The plate is simply supported at the inner edge and isloaded with a circular line load at a radius of 1.8 inches. The deflection at thefree outer edge is compared with results published in Roark and Young 1975.

The results published in Roark and Young 1975 give both the bending and the

shear contribution to the edge deflection. Three models are created for the

example. The first model (Example 2-012a-thin) uses the thin plate option for the

shell elements. Because the thin plate formulation does not include the effects ofshear deformations, the results of the thin plate model are expected to compare

with the published bending deflection.

The second model (Example 2-012a-thick) uses the thick plate option. Because

the thick plate formulation does include the effects of shear deformations, theresults of the thick plate model are expected to compare with the sum of the

published bending and shear deflections.

The third model (Example 2-012b-thick) again uses the thick plate option but

includes area object shear stiffness modifiers v13= 1,000 and v23= 1,000. Those

stiffness modifiers make the shell element 1,000 times stiffer in shear and thusmake the shear deflection negligible. The results of the thick plate model with

shear stiffness modifiers are expected to compare with the published bending

deflection.

The annular plate is meshed 6x96 (radial by tangential).

The circular line load is applied as a distributed load to dummy frame elements.

All of the property modifiers for the dummy frame elements are set equal to zero.Thus, the dummy frame elements have no stiffness.


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COMPUTERS &

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REVISION NO.: 0

EXAMPLE 2-012 - 2

GEOMETRY, PROPERTIES AND LOADING

X

Y 0.5 inch thick annular plate, simply

supported around inner edge, free

around outer edge, with a 6 x 96mesh (radial by tangential)

Innerradius=1.4"

Outerra

dius=2"R

adiu

sto

line

load

=1.8"

E = 18,000,000 lb/in2

= 0.3

G = 6,923,077 lb/in2

Material PropertiesMaterial Properties

800 lb/in line load

shown dashed


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COMPUTERS &

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REVISION NO.: 0

EXAMPLE 2-012 - 3

TECHNICAL FEATURES OF SAP2000 TESTED

Plate bending analysis of shell elements when shear deformations are

significant Area object stiffness modifiers

Frame distributed loads

RESULTS COMPARISON

The independent results are published in the example on page 376 in Roark and

Young 1975. The published bending deflection is -0.00521 inch, the publishedshear deflection is -0.000125 inch and the published combined shear and bending

deflection is -0.00534 inch.

ModelOutput

Parameter SAP2000 IndependentPercent

Difference

A

Thin plate

Uzat outer edge

Bending

Deflection

in

-0.00522 -0.00521 +0.2%

A

Thick plate

Uzat outer edge

Bending plus

Shear Deflection

in

-0.00534 -0.00534 0%

B

Thick plate

with shearstiffness

modifiers

Uzat outer edge

BendingDeflection

in

-0.00521 -0.00521 0%


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