Table of Contents
Linear elastostatics
Computational flowchart
Computational steps
1. Processing the mesh
Input data are written to the text file name.i1.
All element types can be used with the exception of the sandwich and thermal contact resistance elements, which are designed for heat transfer computations only.
| Program | RMD2 (2D problem) / RMD3 (3D problem) |
|---|---|
| Inputs | name.i1, alternatively name.NOD and name.ELE |
| Log | name.o1 |
| Outputs | binary files |
| Details | Computation overview, Mesh / Reference Manual: Inputs, Element library, Input data specification |
2. Processing the material properties and boundary conditions
Input data are written to the text file name.i2.
If a temperature or displacement field is available from a previous computation, it can be read directly from the binary file name.TEM or name.SOL, respectively.
| Program | RPD2 (2D problem) / RPD3 (3D problem) |
|---|---|
| Inputs | name.i2, binary files from the previous step, name.TEM (optional), name.SOL (optional) |
| Log | name.o2 |
| Outputs | binary files |
| Details | Computation overview, Material properties, Supports, Loads / Reference Manual: Inputs, Quantities, Input data specification |
3. Calculating the stiffness matrices and load vectors
Input data are written to the text file name.i3.
Usually, only the restart key $\mathtt{KREST}=1$ is specified, which means assembling the element stiffness matrices and the load vectors (right-hand side vectors) for the load cases processed in the previous step.
It is recommended to check the resultant forces and moments in the log file name.o3.
| Program | SRH2 (2D problem) / SRH3 (3D problem) |
|---|---|
| Inputs | name.i3, binary files from the previous steps |
| Log | name.o3 |
| Outputs | binary files |
| Details | Computation overview / Reference Manual: Inputs |
4. Solving the system of equations
Input data are written to the text file name.i4.
Usually, only the restart key $\mathtt{KREST}=1$ is specified, which means assembling and factorizing the global matrix and performing back-substitution for the right-hand side vectors processed in the previous step.
If the program is terminated prematurely due to a zero or negative pivot, it means that the incorrectly specified boundary conditions allowed rigid body motion.
| Program | FEFS (2D / 3D problem) |
|---|---|
| Inputs | name.i4, binary files from the previous steps |
| Log | name.o4 |
| Outputs | binary files (the solution is in the name.SOL file) |
| Details | Computation overview / Reference Manual: Inputs |
5. Calculating the strains and stresses
Input data are written to the text file name.i5, where the problem type key is $\mathtt{KPROB}=0$.
It is recommended to check the equilibrium of applied forces and reactions in the log file name.o5, which represents the criterion for the accuracy of the solution.
| Program | STR2 (2D problem) / STR3 (3D problem) |
|---|---|
| Inputs | name.i5, binary files from the previous steps |
| Log | name.o5 |
| Outputs | name.STR (optional), name.STB (optional) |
| Details | Computation overview / Reference Manual: Inputs |