final report kunal

7/31/2019 Final Report Kunal

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ASSIGNMENT REPORT

FRACTURE MECHANICS

CE613

By

Kunal R. Umbarkar

08010448

DEPARTMENT OF CIVIL ENGINEERING

INDIAN INSTITUTE OF TECHNOLOGY GUWAHATI

May, 2012


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PROBLEM 1

ABAQUS ASSIGNMENT

1.1 Problem DescriptionDetermine stress intensity factor K1 of rectangular plate with initial inclined boundary crack.

Plate is loaded by unit pressure on both sides of model.

1.2 FE Modelling1.2.1 Geometry and SectionThe general model geometry and loading conditions are shown in Fig. 1.1. The plate

dimensions are 2.5 mm x 5.0 mm. With crack inclined at 300

with respect to horizontal along

the longer side.

The geometry is constructed in Part module as a 2D shell model. The crack is introduced by

partitioning the 2D shell model as shown in Fig. 1.1 by using face partitioning scheme.

Moreover, a circular partitioning is done for sweep meshing.

Mechanical Elastic material with youngs modulus as 30 x 106

and poisons ratio as 0.3 As

given in the problem statement, the model is assigned with solid section of thickness

1 mm.

1.2.2 Crack ModellingIn the interaction module, the crack is assigned. The partitioned edge is firstly assigned a

seam. This feature enables From the special features crack is first defined by assigning crack

front as the crack tip with direction of crack propagation specified by q vectors as shown in

Fig. 1.2. The midside mode parameter is taken as 0.25 for single node, collapsed element side.


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1.2.3 Analysis and LoadingStatic/General Linear analysis is carried out. NLGeom is kept Off for linear analysis . To

obtain KI and KII history output for all 10 counters are requested. Both ends of the plate are

tensioned with a unit pressure.

1.2.4 MeshingFor FE modelling the CPS8R 8 noded biquadratic plane stress quadrilateral elements with

reduced integration technique are used. Throughout the model free meshing is employed

except in the centre where sweep meshing is used.

Global element size is 0.125 mm and inside the circular partitioning 10 elements with biasratio of 1000 decreasing towards crack tip. The normal and zoomed mesh profiles are shown

in Fig. 1.3.

1.3 Results and DiscussionThe final deformed shape is shown in Fig 1.4 with plastic zones near the crack tip (zoomed).

From the Static/General Linear analysis, the average KI is found out to be

and KII is found out to be

..


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Fig. 1.1: Model geometry and loading conditions

Fig. 1.2: Crack propagation


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Fig. 1.3: Mesh profiles

Fig. 1.4: Deformed shape and plastic zones


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PROBLEM 2

MATLAB ASSIGNMENT

2.1 Problem DescriptionPlot plastic zone considering (a) Von-Mises stress criteria and (b) Tresca stress criteria.

Consider either steel or aluminium as material.

2.2 Stress CriterionEquations and blah blah.. explain some small segments of code like normalization..

no need to change matlab code for us. Paste the same code just make minor changes in report.

Material is LDSS i.e. lean duplex stainless steel.. material properties are taken as in the code

2.3 Results and DiscussionPaste the matlab plots here..


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APPENDIX

MATLAB CODE

Paste the code here..

final report kunal

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