equivalent mechanical load
equivalent mechanical load
(OP)
suppose a bar is subjected to a temperature change. I run a thermal analysis to get the temperature distribution in the bar. Later on i want the equivalent mechanical load tht would stress the bar by the same amount. How could i obtain that load? i know that sigma= alpha*delta T where delta T is the temperature difference. But the thing is I have different temperatures at different points in the bar. Could any one tell me how to go about it? Thanks
Kota
Kota





RE: equivalent mechanical load
- Fix all degrees of freedom at all nodes (*Boundary,....)
- Apply stress distribution obtained by thermal analysis to your fully fixed model using *InitialConditions,Type=stress and run a static analysis
- Output the reaction forces and moments. These are the mechanical loads which generates the same stress distribution than the thermal analysis. Possibly that's what your looking for.
Pam
RE: equivalent mechanical load
RE: equivalent mechanical load
RE: equivalent mechanical load
***ERROR: THE FILE PARAMETER IS ONLY VALID FOR INITIAL CONDITION TYPES
TEMPERATURE, FIELD, AND PRESSURE
CARD IMAGE: *initialconditions, type=STRESS, file=al_thermalstrain
*Step, name=load
*output, field
*output, history
*Step, name=load
*Step, name=load
*static
*output, field
*contactoutput
*elementoutput
any idea of whats wrong??
RE: equivalent mechanical load
Pam
Data lines for TYPE=STRESS if the GEOSTATIC, REBAR, SECTION POINTS, and USER parameters are omitted:
First line:
Element number or element set label.
Value of first (effective) stress component, axial force when used with the *BEAM GENERAL SECTION or *FRAME SECTION options, or direct membrane force per unit width in the local 1-direction when used with the *SHELL GENERAL SECTION option.
Value of second stress component.
Etc., up to six stress components.
Give the stress components as defined for this element type in Part V, “Elements,” of the ABAQUS Analysis User's Manual. Stress values given on data lines are applied uniformly over the element. In any element for which an *ORIENTATION option applies, the stresses must be given in the local system (“Orientations,” Section 2.2.5 of the ABAQUS Analysis User's Manual).
Repeat this data line as often as necessary to define initial stresses in various elements or element sets.
RE: equivalent mechanical load
RE: equivalent mechanical load
Pam
RE: equivalent mechanical load
Following on from Pams idea, simply add another step to your analysis. Fix the displacements from your first thermal analysis step using '*boundary,fixed' and fix the degrees of freedom as pam suggests. This should hopefully give you the loads you're after as reactions.
Matt
RE: equivalent mechanical load
RE: equivalent mechanical load