Page 32 - Finite Element Modeling and Simulations with ANSYS Workbench

Introduction 17

TABLE 1.2
Indicator Icons and Descriptions of the Various Cell States
Cell State Indicator Description
Unfulfilled Need upstream data to proceed

Refresh required A refresh action is needed as a result of changes made on
upstream data

Attention required User interaction with the cell is needed to proceed

Update required An update action is needed as a result of changes made on
upstream data

Up to date Data are up to date and no attention is required

Input changes pending An update or refresh action is needed to recalculate based
on changes made to upstream cells
Interrupted Solution has been interrupted. A resume or update action
will make the solver continue from the interrupted point
Pending Solution is in progress

Source: Courtesy of ANSYS Workbench User’s Guide, Release 14.5, ANSYS, Inc., 2012.

In the chapters that follow, the use of ANSYS Workbench will be presented in a step-by-
step fashion in the context of real-world problem solving that may involve different mod-
eling concepts or different physics. It is worth noting that, although a commercial finite
element program enables you to deal with a wide range of engineering problems with
complex geometry, constraints, and material behaviors, it is your responsibility to under-
stand the underlying physics to be able to setup a problem correctly. Your FEA results, no
matter how pretty they may look, are only as good as the assumptions and decisions you
have made in building your model.

1.4 Summary
In this chapter, the basic concepts in the FEM are introduced. The spring system is used
as an example to show how to establish the element stiffness matrices, to assemble
the finite element equations for a system from element stiffness matrices, and to solve
the FE equations. Verifying the FE results is emphasized. ANSYS Workbench environ-
ment is briefly introduced. The concepts and procedures introduced in this chapter are
very simple and yet very important for studying the finite element analyses of other
problems.