Status code: 9 MATRIX_Singular_OR_INDEFINITE

Some error messages make you wonder, what does it take to get something simple done? I have often wondered how coders come up with names for errors and claim them to be logical? One common bane is “Status code 9." This message is often followed by a second message claiming there aren’t enough restrains defined.

Basically, the software cannot figure out how parts are interacting in 3D space. Every solid or surface body has six degrees of freedom available to it (three translational and three rotational). When users define loads and restraints they remove degrees of freedom from the model.  Behind the scenes (in SolidWorks) equations are being written to solve for deformation and strength of components. The equations are balanced out using generated reaction forces. If there are not enough conditions defined, i.e. the software cannot identify what is happening in a specific direction, equilibrium is not achieved and hence the solution fails.

Is there a magic button that makes all this go away? I usually refrain from making blatant promises. But an honest answer would be Yes and No!

 

 

 

 

 

 

 

Use Soft Spring to stabilize a model

Using Soft Spring to stabilize a model is a good way to make things work. Users can reach this by accessing study property. This adds artificial spring stiffness to the model eliminating rigid body modes. The stiffness value added is very small and can be neglected in most cases, but it is recommended to correct this approximation. One good technique is to check displacements in x,y and z directions. The direction in which there is the most displacement needs to be restrained.

Use inertial relief

This does exactly the same thing as the Soft Spring option in a different fashion. Inertial relief (as the name suggests) will add artificial mass in directions needed. This option is especially useful if loads are imported from motion analysis.

Do not use both the Soft Spring and inertial relief options at the same time. They would be counterproductive. If both are used in conjunction, the software will make significant assumptions and generate erroneous results.

Rajat Trehan

Product Manager – Design Validation

Computer Aided Technology Inc.

Comments

[Thanks]

This helps a lot! Thanks!