Blog Articles

Demonstration of how you can use the PolyUMod Material Database model for LLDPE. This is an excellent model for generic LLDPE.
Most tests are in displacement control, but residual strain is measured in load control. This article explains how to use this mixed data.
BAM Model
One way to quickly improve the accuracy of the Arruda-Boyce model is to add one more strain energy funcion.
Gent Hyperelasticity
Gent hyperelasticity theory and parameter calibration. The Gent model is available in Ansys Mechanical and COMSOL Multiphysics.
This article presents 3 reasons the Poisson's ratio is not useful, and also explains how you can fix the problems.
Part 3 in our series on how to calibrate a material model from tension force data. This article focuses on using Abaqus for the calculations.
Part 2: Calibrating a material model from tension with necking experimental data is surprisingly difficult. This article explains one approach to do it.
Abaqus 2022 contains some really nice improvements for Linux users. This article summarizes the key improvements.
Part 1: Tutorial on how to predict the cold drawing or necking response of thermoplastics (such as polycarbonate).
Tutorial on how to make the PolyUMod TN and TNV models better capture the stiffness non-linearity before yielding.
The Blatz-Ko model can be used for both foams and rubber-like materials. This article explains the theory.
This article examines which material model is best for PEEK. Some of the basic plasticity models are surprisingly bad.
Anisotropic materials often need an effective strain measure. The Hill strain is useful in those cases.
Definition of the Hill Stress and how to use it in material models.
This video shows how you can work with, and change to different units in MCalibration.
Version 6.4.0 of PolyUMod includes 2 advanced UCREEPNETWORK and VUCREEPNETWORK models that can be used with the Abaqus PRF model.
This article examines the difference between simple shear, pure shear, and planar tension.
It would be very handy if uniaxial compression was the same as biaxial tension. But is it? This article has the answer.
Investigation of how important the bulk modulus is in a FE simulation. Using MCalibration and Abaqus, I show that most of the time the bulk modulus has virtually no influence
MCalibration can calibrate all solid mechanics material models in COMSOL Multiphysics. This tutorial shows how.
Demonstration of how you can quickly calibrate the Extended Tube Model that is available in COMSOL Multiphysics.
The preload time is important when you analyze a stress relaxation experiment. This article explains why.
Tutorial showing how you can take experimentally stress relaxation data at different temperatures and create both a master curve and a linear viscoelastic material model that captures all the data.
Tutorial on how to extract the data from an image of a graph into either an external data file or MCalibration. The data extraction allows for the use of cubic
Theory of how the constitutive elements influence the predicted yield stress dependence on strain rate
Review of how different material models can be used to predict the non-linear response of PC. Also covers how the yield stress depends on the strain rate.
Video tutorial showing how to remove one load cycle from an experimental test.
Quick discussion about the math behind stress relaxation and creep in polymers.
Discussion about how to extrapolate the stress relaxation response of rubbers to long times.
Discussion about how to best estimate the long-term stress relaxation response of a thermoplastic based on short-term data.