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Abstract First-order martensitic transformations usually undergo temperature variations because of release/absorption of latent heat. Such temperature variations, in turn, affect the process of phase transition and the propagation of phase boundary, especially for shock loading. In fact, the phase transition wave front is not only a discontinuity of mechanics and matter, but also a moving temperature interface. This temperature interface is bound to influence the phase transition wave profiles and make the space-time pattern of its propagation more complex. However, it may bring some new wave propagation phenomena, which will have important theoretical value for the extension of stress wave theory. In this paper, the effect of temperature on the propagation of phase transition wave was studied theoretically and numerically. First, we treated the temperature interface as a fixed one to study the basic interaction between the temperature interface and phase transition wave by using the method of one-dimensional characteristic line theory and finite difference numerical calculation. The results showed that such an interaction was related to the temperature gradient of the interface and the applied stress pulse amplitude. Second, the propagation of phase transition wave was given under the conditions of continuous temperature gradient and adiabatic impact, respectively. The results showed that for loading from the austenitic phase to the mixed phase or martensite phase, a shock wave would be generated due to the mixed phase hardening effect; while for unloading, a shock wave was predicated due to a change in the unloading path, which has barely been studied. Through analysis of the thermo-mechanical coupling constitutive equations with phase transition, it was found that the nonlinear hardening characteristics and the change of unloading path are both rooted in the interaction between the self-heating (latent heat and dissipated energy) and the temperature dependence of phase transition stress, reflecting the intrinsic characteristics of materials with strong thermo-mechanical coupling properties. The results are helpful for the design and control of impact resistance for phase transition materials and structures.
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Received: 03 July 2020
Published: 14 April 2021
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2021, Vol. 42 
