The appropriate constitutive law for modeling crack propagation in High-Density Polyethylene (HDPE) using Ansys is a subject of debate among experts. The discussion highlights that HDPE can exhibit large strains, up to 600% in tensile tests, and presents challenges in defining a suitable constitutive equation. While some researchers propose an elastic-viscoplastic model, others suggest an elastic-plastic approach, raising questions about the adequacy of these laws for HDPE. The determination of viscoplastic parameters requires specialized experimental data, complicating the modeling process.
PREREQUISITESMaterial scientists, mechanical engineers, and researchers involved in polymer modeling and simulation, particularly those focusing on HDPE and crack propagation analysis.
There are lots of constitutive equations out there that describe viscoelastic materials qualitatively, in terms of a set of material parameters. However, I know of none that are capable of describing the behavior of a real material like HDPE quantitatively for an arbitrary deformation. So, even though you can make laboratory measurements to determine a set of material constants, unless the kinematics of the deformation experienced in the field is very close to the laboratory kinematics, the model will not make accurate predictions for the actual field kinematics.zerrouki said:there are some authors who state that the constitutive law is elastc-viscoplastic. but the difficulty is how to determine the parameters of the viscoplastic part ?? take in account that these parameters need experimental data that require special machine to do the tests. Furthermore, there are others that declared the constitutive law as elastic-plastic, but, is this law appropriate for HDPE ??
I'm not familiar with that model. Sorry.zerrouki said:i thought to use perzyna option to model the viscoplastic behaviour of the HDPE, have you some informations about this model ? ( if it can work with large deformation or with just small ones ?).