ANSYS APDL ASSIGNMENT PDF

Preview

Summary

NAME: JIGIASU KUMARENTRY NO: 2019MEMLAB ASSIGNMENT 9CAD & FEMMCL 735 -ANSYS LAB 9Plane stress analysis For the given structure (figure) under tension, model the system using geometrical and loading symmetry, perform the following using ANSYS Using first order planar element (Solid-Quad 4 nod...

Description

NAME: JIGIASU KUMAR ENTRY NO: 2019MEM2838 LAB ASSIGNMENT 9 CAD & FEM

MCL7 3 5ANSYSLAB9 Pl a nes t r e s sa na l ys i s For the given structure (figure) under tension, model the system using geometrical and loading symmetry, perform the following using ANSYS 1. Using first order planar element (Solid-Quad 4 node element) of edge length 20mm: a. Determine the displacement (vector-sum) distribution and von Mises stress distribution in the plate due to the applied loading and boundary conditions. b. Determine the maximum stress in the x-direction for point A. c. Plot the von Mises stress along the vertical line of symmetry AB. d. Determine the shear stress in XY plane along the lines of symmetry AB and CD. 2. Reanalyze using element edge length 10mm and 5mm and compare the effect of the number of elements on the solution of stress attained at A. 3. Change the element type to a second order element (edge length 5mm), reanalyze and compare the effect of element type on the solution of stress attained at A.

Note: Thickness of the plate is 10mm. The stress value at A from analytical result is 312.5N/mm 2 (this is for comparing the results from above analysis). E = 210000 N/mm2, υ = 0.3, a = 200 mm, b = 100 mm, r = 10 mm, σ = 100 N/mm 2

Prepare the report describing: 1. Snapshots showing various steps in modeling for Q1 2. Snapshots with loads and constraints applied for Q1 3. Snapshot showing the meshed model for Q1 to Q3 4. Results for Q1 to Q3 5. Your understanding and conclusion/comments on the effect of number of FE elements used on accuracy of results.

Various Steps involved STEP 1: Click on  Preferences  Structural  ok

STEP 2: You can model your part first or can define the elements first there will be no difference if order is not followed. In screenshot I have modeled the shape first and then defined the element properties but in step I am describing defining element first. Preprocessor  Element type  Add Solid Quad 4 node 182  ok

STEP 3: Now add thickness to the defined element type. For this follow:

Preprocessor  Element Type  Add/Edit/Delete  Select the element plane 182  Options  Change Element behavior K3 as Plane strs w/thk  ok.

After that go to Preprocessor  Real Constants  Add/Edit/Delete  Add  Select Plane 182  Ok  Add thickness in THK column and click ok.

STEP 4: Preprocessor  Material Props  Material Models  Material Model Number 1  Structural  Linear  Elastic  Isotropic  Enter the value of Young’s Modulus as 2.1e5 & Poisson’s ratio as 0.3  ok

STEP 5: Modelling of the 2D shape. Since the model is symmetric about two axis so we will model the 1/4th part only. Modelling itself involves several steps so I will be explaining those as a,b,… a. Preprocessor  Modelling  Create  Areas  Rectangle  By 2 corners  and put X and Y coordinate as (0,0) and width as 100 and height as 50  ok

b. Now in similar way create a circle with center at (0,0) and radius as 10.

c. Now subtract the circle from rectangular area by following the steps: Preprocessor  Modelling  Operate  Booleans  Subtract  Areas  Pick rectangle first  okay  then pick Circle ok.

This completes the modelling part and our 2D shape is ready for further processing.

STEP 6: Preprocessor  Meshing  Mesh Tool  Set Global element edge length as 20  ok  Mesh  Select area  ok.

STEP 7: Now add boundary conditions of symmetry. Preprocessor  Loads  Define Loads  Apply  Structural  Displacement  Symmetric B.C.  On lines  Select both the lines of symmetry  ok

STEP 8: Apply loads as: Preprocessor  Loads  Define Loads  Apply  Structural  Pressure  On lines  Select Direction as FX and fill magnitude as -100.

STEP 9: Solution  Solve current LS  Ok. Generating the Displacement Vector sum and Von misses contour plot is same as in the previous 2 cases. I will give steps to get Von misses Stress at Point A.

General Postproc  Query results  Subgrid Solution  Select stress  X Direstion SX  Ok  Pick Point A and click ok.

Steps to generate Von-Misses or Shear stress Vs X graph along any arbitrary line i.

General Postproc  Path Operations  Define Paths  By Nodes  select the first and last node along the path  ok  Define your path name  ok.

ii.

General Postproc  Map onto Path  Enter user label for item  Select Stress  VonMisses For Von misses and Shear XY for shear stress  ok.

iii.

General Postproc  Plot Results  Plot Path Item  On graph  Select path item to be graphed  okay.

Graph will be generated as

Required Snapshots of Mesh and Defined Boundary conditions With Quad 4 node element and Element Size 20.

With Quad 4 node element and Element Size 10.

With Quad 4 node element and Element Size 5.

With Second order element and Element Size 5.

Von-Misses Plot

Displacement Vector Sum Plot

Plot of Von Misses Stress along line of symmetry AB

Plot of Shear Stress in XY Plane along Line of symmetry AB

Plot of Shear Stress in XY plane along line of symmetry CD

Maximum Stress at A i.

With Quad 4 Node with element size 20

ii.

With Quad 4 Node with element size 10

iii.

With Quad 4 Node with element size 5

iv.

With Second order element with element size 5

Comparison Table of Max. Stress at A in Four Cases Analysis Type Quad 4 node with Element Size 20 Quad 4 node with Element Size 10 Quad 4 node with Element Size 5 Second Order Element with size 5 Exact Method of SOM

Stress at A (in MPa) 134.39 241.65 289.75 300.761 312.5

From the above table one can easily observe that the Analysis using element Quad 4 node with Element Size 20 is worst and produces result which is nowhere near to exact ans. However on increasing the no. of elements i.e. reducing the element size produces result closer to the exact solution. One can also observe that with same element size accuracy is more with Second order element that Quad 4 node element....