Finite Element Analysis Lab

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15 Νοε 2013 (πριν από 3 χρόνια και 4 μήνες)

56 εμφανίσεις

Dr. O’Malley
Spring 2013


MENG
-
421L

MENG 421L

Finite Element Analysis Lab

Introduction to Computer Based FEA
Using Ansys


MENG
-
421L

Lab Structure


Class Format


20% of Overall Grading


Lab Reports


Class Rules


Come to Class and Don’t be Late


Memos Due on Thursday by 12:00 noon in
Department Office Weir 122


No Late Lab Reports

Dr. O’Malley
Spring 2013


MENG
-
421L

Topics


Truss and Spars


Plane Strain and Stress


Axisymmetric Techniques


Tetrahedron and Brick Elements


Shell Type Element


Thermal Stress


P
-
Method


A Little Workbench

Dr. O’Malley
Spring 2013


MENG
-
421L

Finite Element Method (FEM)


Common Applications of FEM


Stress


Deformations


Heat Transfer


Fluid Flow


Circuits and Electromagnetics


Dr. O’Malley
Spring 2013


MENG
-
421L

The FEM Process


Preprocessing


Build the FEM Model


Solver (Processing)


Solves the Equations


Postprocessing


Display and Evaluate the Results

Dr. O’Malley
Spring 2013


MENG
-
421L

Start Ansys Product Launcher

Dr. O’Malley
Spring 2013


MENG
-
421L

Dr. O’Malley
Spring 2013


MENG
-
421L

Two Approaches to Ansys


Graphical Interface


Easy to Use and Somewhat Straight Forward


Hard to Save FEM Setups


Can’t “Go Back”


Batch Files


Written Ansys Code


Text Files


Easy to Save


Serve As Templates or Starting Points of Analysis (The
FEM)

Dr. O’Malley
Spring 2013


MENG
-
421L

Ansys Batch Coding


Code Structure


Preprocessor


Processing (Solver)


Post Processor


Code Format


Commands


Element types


Analysis types


Etc.

Dr. O’Malley
Spring 2013


MENG
-
421L

How to Approach The Problem
(Preprocessor)


Determine the Type of Elements That We Will Need


Assign Required Geometric Properties for the Elements


Assign Required Material Properties


Create the Mesh


Place All of the Nodes


Place Appropriate Elements Between the Nodes


Assign Boundary Conditions


Assign the Loads to the FEM


Dr. O’Malley
Spring 2013


MENG
-
421L

Selecting An Element


Help Menu


Element Library


Spar


Trusses


Tension and Compression (only)


Plane Stress Elements


Shells


Bricks


Tetrahedrons


Beam Elements

Dr. O’Malley
Spring 2013


MENG
-
421L

Preprocessing


Programming in Batch (Preprocessor)


Read Input From…


Display Model Graphically


Plot Controls


Numbering
-

Turn On Node and Element Numbering


Symbols


Turn On “All Applied BCs”


Plot Elements


The “File”


Dr. O’Malley
Spring 2013


MENG
-
421L

Processing and Postprocessing


Run the Current LS (Load Step)


Plot Results


General Postproc > Deformed Shape


List Results


Nodal Solutions


General Postproc > List Results > Nodal Solution > DOF
Solution > Displacement Vector Sum > OK


Element Solutions


General Postproc > List Results > Element Solution > Line
Element Results > Elements Results > OK




Dr. O’Malley
Spring 2013


MENG
-
421L

The Report


Problem Statement in a Clear and Professional Manner


Approach


Element Definitions


Assumptions


Loading and BC


state loads


Techniques,
ect
.


Results
-

Discussion and Interpretation


Plots


Tables


Conclusion


try to figure out why and describe problems


be creative


Problems, Recommendations, Explanations




Dr. O’Malley
Spring 2013