论文部分内容阅读
随着科学技术的迅猛发展,材料在高温领域的应用越来越广泛.然而高温下材料的力学性能和常温相比有很大差异,材料的高温力学性能研究和表征已成为当前的研究热点.论文对材料在高温下力学行为理论表征方法研究的最新进展进行了总结和回顾.着重介绍了近年来高温陶瓷材料的断裂强度、金属材料的屈服强度、弹性模量与本构关系的温度相关性理论表征方法的研究进展.最后,总结已有研究工作的特点和不足之处,对材料高温力学性能理论表征方法的后续研究进行了展望,就进一步研究提供建议.“,”With the rapid development of science and technology,materials are more widely applied in high-temperature fields.Ceramic materials,as one of the most potential high-temperature candidates,can be applied in the thermal protection system of hypersonic flight vehicles,the high-temperature components of engines and the key components of nuclear fission reactors.Meanwhile,metal materials also play a very important role in high temperature applications,and have been widely used as the high-temperature structural components.Because their mechanical properties at elevated temperatures are quite different from those at room temperature,studies and characterizations on the high-temperature mechanical properties of materials have become the hotspot of current research.Although theoretical studies on the mechanical properties of these two kinds of materials at room temperature are quite sufficient,the theoretical characterizations of their mechanical properties at different temperatures,especially at elevated temperatures,are still lacking.Recent developments in the theoretical characterization methods for the temperature-dependent mechanical behavior of these materials are summarized and reviewed in this paper.A novel modeling idea for the temperature-dependent mechanical properties of materials is mainly introduced by considering that:‘ (1) there exists the maximum energy storage capacity for a particular material,and this capacity can be measured by both strain energy and heat energy;(2) there exists a quantity-equivalent relation between strain energy and heat energy’.And this modeling idea has been applied to characterize the mechanical properties including:(1) the temperature-dependent fracture strengths of ceramic materials,mainly including the ultrahigh-temperature ceramics,particle-reinforced ceramic matrix composites,laminated ceramic matrix composites and fiber-reinforced ceramic matrix composites;(2) the temperature-dependent yield strengths of metal materials,including pure metals and alloys;(3) the temperature-dependent elastic moduli of metal materials.In addition,the constitutive relation of metal materials at elevated temperatures and high strain rates is also introduced.Finally,future studies on the theoretical characterization methods for the high-temperature mechanical properties of materials are prospected.Some suggestions are provided for the future work by summarizing the characteristics and deficiencies of existing research.