Shrinkage models

There are several shrinkage models used in this product, depending upon how much information about the material is available in the Midplane, Dual Domain, and 3D solutions.

The following options are available:

Shrinkage model (Midplane and Dual Domain)

Uncorrected residual stress

This option will be selected when there is no shrinkage data available for the material. In this case, the Fill+Pack analysis predicts the residual stress values within in the part, based on the flow and thermal history during the molding cycle.

Corrected residual in-mold stress (CRIMS)

This option is the default when shrinkage testing has been performed on the material. This model is the most accurate because it is obtained by correlating actual tested shrinkage values with Fill+Pack analysis predictions.

Residual strain

This option is selected for those materials where the CRIMS model was found to not adequately describe the shrinkage behavior of the material.

Shrinkage model (3D)

Generic shrinkage model

This model has been superseded by the Uncorrected residual stress model. You can use it for all thermoplastic and thermoset processes, however, you cannot use it with some Solver API options.

Uncorrected residual stress (3D)

This shrinkage model calculates molded-in residual stresses which it passes as inputs to the 3D warp analysis. This is the default shrinkage model for all 3D analyses. You can use it with all thermoplastic and thermoset processes.

Note: When you use this model, the following messages appear in the analysis log:

Shrinkage test adjusted mechanical properties (STAMP)

This shrinkage model calculates molded-in residual stresses which it passes as inputs to the 3D warp analysis. Before calculating the residual stress values, this model calibrates the modulus, Poisson's ratio and coefficient of thermal expansion according to measured shrinkage data for the selected material. You can only use this model for thermoplastic materials which have measured shrinkage data.