Experimental characterization of self-heating at intermediate strain rates for elastomers and evaluation of thermoelastic hyperelastic constitutive model

In this research, the rate sensitivity and associated self-heating phenomena of elastomers due to constant high strain rate loading is characterized by a comprehensive experimental method. The experimentally observed material behavior is later predicted by numerical simulation using a modified thermo-elastic hyperelastic material model. To achieve the research goals, two different elastomeric materials RTV 630 and Flexane 94 were tested in four different deformation modes: uniaxial tension (UT), uniaxial compression (UC), planar tension (PT), and volumetric compression (VC) using conventional and newly designed light weight test fixtures at different nominal strain rates (0.01 s^-1 to 100 s^-1). Experimental results showed that both materials are strain rate sensitive and exhibit self-heating at all deformation modes when the strain rate loading is greater than 0.01 s^-1, except for volumetric compression which indicates that the self-heating at high rate loading is dictated by the deviatoric component of deformation not the hydrostatic component. The magnitude of self-heating was significant for uniaxial loading cases and it is dependent on material types, strain rates and strain levels. The appropriate hyperelastic material model was first identified and evaluated by using the test data and curve fitting methods. Then the material model was modified and implemented in a commercial finite element program to predict the materials experimentally observed non-isothermal behavior by numerical simulation using a single element model. Afterwards, the prediction capacity of the material model was further evaluated and validated by scaling the material parameters of highest strain rate (100s^-1) loading. Overall, a good agreement was observed between the predicted behavior of the modified material model and test data.

Author

• Siddiqui, Md Tareq

Identifier

hdl:10057/55548

OAI identifier oai:identifier

oai:soar.wichita.edu:10057/55548