“屈服点”是工程结构研究和设计中一个极为关键的性能点,是衡量延性、屈强比等性能的前提,但在当前结构设计中尚缺少统一的定义。随着新型结构材料的不断出现,新的构件行为也在不断出现,作图法、等能量法、残余塑性变形法等确定屈服点的方法不能适用。该文首先从材料层次基于金属单轴拉伸屈服点的定义,给出了金属、混凝土和纤维增强复合材料等典型材料的屈服点定义的统一表述;再从构件和结构层次,基于应用条件与物理本质,明确了屈服点的定义方法,为新型材料构件、结构设计提供了依据,并对钢筋混凝土梁和短柱使用此方法进行了讨论。此外,还建议采用“最远点法”确定构件和结构的屈服点,该方法具有明确的物理含义,且适用性广、适合于电算。通过分析构件和结构的试验结果表明建议的屈服定义和提出的最远点法具有一致性和合理性,从而从基本原理和定义方法上明确了材料、构件和结构屈服点。 “Yield point ” is an extremely important performance point in the research and design of engineering structure. It is a prerequisite to measure ductility, yield ratio and other performance. However, there is a lack of uniform definition in current structural design. With the continuous appearance of new structural materials, new component behaviors are emerging constantly. The methods of determining yield point, such as plotting method, isoelastic method and residual plastic deformation method, can not be applied. Based on the definition of the uniaxial tensile yield point of the material, the paper gives the uniform expression of the yield point definition of typical materials such as metal, concrete and fiber reinforced composites. Based on the application and conditions, Physical definition, the definition of the yield point is defined, which provides a basis for the new material components and structural design, and discusses the use of this method for reinforced concrete beams and short columns. In addition, it is also recommended to determine the yield point of components and structures using the “farthest point method”, which has a clear physical meaning and is suitable for computing. The test results of component and structure show that the proposed yield definition and the proposed farthest-point method are consistent and reasonable, and the yield points of materials, components and structures are clearly defined from the basic principles and the definition methods.