受弯构件的变形性与新的性能指标的研究

提出用变形性代替传统延性的概念以适应使用了新型材料(如纤维增强复合材料,即FRP)的受弯构件的荷载-变形关系的多样化.通过分析已有的性能指标,定义了设计目标状态和极限破坏状态作为构件的性能特征状态,并提出一组新的性能指标:变形性系数D、承载力系数S、变形能系数Y和综合性能系数F,用以全面地描述各种构件的性能和安全储备.参照传统构件,分析了5种受弯构件的数值计算结果,获得了各性能指标的取值范围及它们之间的关系,并提出可以通过提高构件承载能力来弥补其变形储备不足从而保证总体安全储备不变.建议用F指标来确定各种受弯构件的设计目标状态,从而获得合理且一致的安全性储备,并以8个试验构件为例进行了计算,验证了其合理性.包括变形性在内的性能指标的提出,为新型材料结构设计提供了参考.

DEFORMABILITY AND NEW PERFORMANCE INDICES OF FLEXURAL MEMBERS

Instead of conventional ductility, deformability is proposed for various load-deformation curves of members made of new materials, such as fiber reinforced polymer (FRP). After analyzing the existent performance indices, the design-aimed state and the ultimate failure state are defined as the characteristic behavior states for members. Moreover, a set of performance indices, including deformability factor D, strength factor S , deformation energy factor Y and overall performance factor F, are presented to describe the behavior and the safety storage of flexural members comprehensively. Comparing with the traditional members, the relation among the performance indices is analyzed by the numerical results of five types of members and the ranges of the indices are acquired. It is drawn that the safety storage for strength and deformation can be exchanged without overall safety margin loss. F factor is suggested to serve as the scale for determining the design-aimed state, by which the reasonable uniform safety storage for various flexural members can be acquired. It is proven by evaluating eight specimens in references. The proposal of the performance indices including deformability provides a reference for the design of members made of new materials.