INSTANTANEOUS THERMAL EXPANSION BEHAVIOR OF HETEROGENEOUS MATERIALS WITH A WORK-HARDENING ELASTOPLASTIC MATRIX AND ELASTIC SPHEROIDAL INHOMOGENEITIES

摘要

The instantaneous thermal expansion behavior of two-phase hetero-geneous materials subjected to a uniform temperature change is explored in the presentstudy.The matrix phase is assumed to be a work-hardening ductile metal and thedispersive phase is assumed to consist of either aligned or randomly-oriented,elastic,spheroidal inhomogeneities.The plastic flow and decreasing stiffness of the matrixduring Eshelby’s transformation strain of the equivalent inclusions are accounted for byusing the deformation theory of plasticity.The explicit results of the instantaneousoverall thermal expansion coefficients and the critical inelastic temperature changes arepresented for aligned disc-and fiber-inclusions.For the spherical and randomly-oriented spheroidal inclusion,the present study demonstrates that when the yielding ofthe composites is governed by the average matrix stress,the overall response is alwayselastic in spite of the temperature change.