Zhu‐Wang‐Tang constitutive model of reinforced Al/PTFE materials at medium strain rate

Abstract

Aluminum/Polytetrafluoroethylene (Al/PTFE) active materials have the dual characteristics of strength and activity. When acting on the target, it penetrates first and then deflagration, so as to enhance the damage effect on the target. Based on the traditional formula of Al/PTFE (26.5%/73.5%), the reinforced Al/PTFE active materials are prepared by cold pressing sintering and rapid cooling process. The static and dynamic compression experiments are carried out on this material. Based on the compression experiment data, the Zhu‐Wang‐Tang (ZWT) constitutive model parameters of the reinforced Al/PTFE active materials are fitted. The self‐made ZWT constitutive model subroutine is embedded into ABAQUS by the user material subroutine interface (VUMAT), and the numerical simulation is carried out in the range of medium strain rate (1400–3300 s−1). The accuracy of the parameters of the constitutive model is verified by the combination of experiment and numerical simulation. The results show that the reinforced Al/PTFE materials have better mechanical properties under dynamic loading than the traditional formula Al/PTFE. When the strain rate is 1400 s−1, the maximum stress of the reinforced Al/PTFE materials is 54 MPa, which is 1.5 times the strength of the traditional formula Al/PTFE; when the strain rate is 2800 s−1, the maximum stress of the reinforced Al/PTFE materials is 100.3 MPa, which is 1.9 times that of the traditional formula Al/PTFE. In the range of strain rate from 1400 to 2800 s−1, the time‐history curves of true stress, true strain, and strain rate obtained by numerical simulation are in good agreement with the experimental results. It is extrapolated to the loading strain rate of 3300 s−1, and the numerical simulation results are still in good agreement with the experimental results. The compressive ZWT constitutive model of reinforced Al/PTFE active materials obtained in this paper is reliable and can well describe the dynamic mechanical properties of the material at medium strain rate (1400–3300 s−1).

Determination of Elastic Modulus, Stress Relaxation Time and Thermal Softening Index in ZWT Constitutive Model for Reinforced Al/PTFE

“…For quasi-static and low strain-rate loading conditions, the influence of the high strain-rate Maxwell element is ignored [ 38 ]. The quasi-static loading is a constant strain rate loading, , and the equation is simplified to …”

Effects of different mass ratios on mechanical properties and impact energy release characteristics of Al/PTFE/W and Al/PTFE/CuO polymer composites

“…Additionally, the authors speculated that the initiation phenomenon proceeded in a mechanochemical manner, and a crack‐induced reaction mechanism was proposed 6 . Chen et al 7 conducted dynamic compression tests on Al/PTFE composites at increasing strain rates; at a strain rate of 2800 s −1 , the compressive strength reached a peak of 100.3 MPa. The proposed Zhu‐Wang‐Tang (ZWT) constitutive model fitted well the experimental results obtained on the materials when subjected to intermediate strain rates (1400–3300 s −1 ).…”