A new analytical model for thermal stresses in multi-phase materials and lifetime prediction methods

• 来源期刊: 力学学报（英文版）
• 年，卷（期）: 2008,（2）
• 页码范围: 189-206
• 页数: 18页
• 语种: 英文
• DOI: 10.1007/s10409-008-0132-z

摘要

Based on the fundamental equations of the mechanics of solid continuum, the paper employs an ana-lytical model for determination of elastic thermal stresses in isotropic continuum represented by periodically distributed spherical particles with different distributions in an infinite matrix, imaginarily divided into identical cells with dimen-sions equal to inter-particle distances, containing a central spherical particle with or without a spherical envelope on the particle surface. Consequently, the multi-particle-(envelope)-matrix system, as a model system regarding the analytical modelling, is applicable to four types of multi-phase mate-rials. As functions of the particle volume fraction v, the inter-particle distances d1, d2, d3 along three mutually per-pendicular axes, and the particle and envelope radii, R1 and Re, respectively, the thermal stresses within the cell, are originated during a cooling process as a consequence of the difference in thermal expansion coefficients of phases rep-resented by the matrix, envelope and particle. Analytical-(experimental)-computational lifetime prediction methods for multi-phase materials are proposed, which can be used in engineering with appropriate values of parameters of real multi-phase materials.