When running analyses that contain weld surfaces, it can be useful to perform a calibration or sensitivity study to determine which strength reduction calculations are appropriate for your materials. As a result, Advanced Material Exchange lets you to adjust the weld surface strength calculations with the HIN file. As described below, the HIN file keywords can be used to adjust the analysis, without the need to re-map the Moldflow results to the structural model.
*WELD SURFACE STRENGTH, METHOD=[NONE/CONSTANT/ROBBINS]
The *WELD SURFACE STRENGTH keyword allows you to specify the method used to calculate the weld surface strength and any inputs for the chosen method. If the *WELD SURFACE STRENGTH keyword is used, it will override any weld surface strength calculations stored in the .sif file. This keyword must be preceded by a *MATERIAL keyword. See the HIN File topic for more information about the *MATERIAL keyword.
The default weld surface strength METHOD is NONE.
*WELD SURFACE STRENGTH, METHOD=NONE
In this case, weld surface strength calculations are turned off.
*WELD SURFACE STRENGTH, METHOD=CONSTANT SRF
The CONSTANT method allows you to specify a single strength reduction factor (SRF) for all weld surfaces. SRF must lie in the range 0 < SRF ≤ 1. SRF defaults to a value of 1.0 if left unspecified. An example HIN file setup using the CONSTANT method with SRF = 0.8 is given below.
*MATERIAL, name=CA-Material-1 *WELD SURFACE STRENGTH, METHOD=CONSTANT 0.8
where CA-Material-1 is the user material specified in the input file.
The third available METHOD is ROBBINS.
*WELD SURFACE STRENGTH, METHOD=ROBBINS, MINSRF=minsrf ct1, ct2
The ROBBINS method is used in the automatic calculation of strength reduction factors. MINSRF is an optional parameter that allows you to specify the minimum strength reduction factor. It can be useful to specify a minimum value in order to avoid erroneously small SRF values that can result from noisy data. By default, MINSRF is set to 0.1. MINSRF is only applicable to the Robbins method.
The two terms ct1 and ct2 are the coefficients used in the Robbins method. Any value specified on the data line will override the value of the coefficient stored in the .sif file. ct1 and ct2 default to a value of 0.0 if left unspecified. Refer to the Weld Surface Strengths section of the User's Guide for more information on the Robbins Method.