[笔记][规范][钢结构] 美国规范中的ASD及LRFD

实干、实践、积累、思考、创新。 ASD:allowable stress design 容许应力设计法 LRFD:load and resistance factor design 荷载及抗力系数设计法 美国钢结构规范中的两种设计方法及两种荷载组合方法。 其中ASD是容许应力设计,设计思路可以简单理解为,考虑一个安全系数,使得设计的 实际应力需求< 材料强度/ 安全系数,通过一个安全系数来确定结构的可靠度。LRFD应该是类似目前我们国内使用的 概率极限状态设计法,就是将荷载效应及结构的抗力均看做随机变量,以结构失效概率确定结构的可靠度,实际操作过程中则是通过分项系数乘以标准值的方式,获得荷载效应及结构抗力的设计值,并进行对比。 相关博文( Related Topics) [01] [工具][软件][规范] 广东省标准《高层建筑混凝土结构设计规范》反应谱计算工具 [02] [结构力学][结构设计] 两端固支梁弯矩为0点距端部的距离 [03] [抗震][结构设计][规范] 非抗震设计情况下混凝土柱的“轴压比”可达多大? [04] …

[Tool][软件][性能设计] PPPSP v2017: Pushover Performance Point Solution Program [Pushover 分析性能点求解程序][Based on FEMA 440]

[Tool] 基于FEMA 440等效线性化法 Pushover分析方法 的性能点求解程序。A program for the Solution of Pushover Performance Point based on FEMA 440 Equivalent Linearization Method. FEMA 440等效线性化方法是众多Pushover分析方法中的一种,是ATC-40能力谱法(Capacity-Spectrum Method )的一种改进,其基本原理如下图所示。( Equivalent linearization procedure of FEMA 440 is a modification to the Capacity-Spectrum Method (CSM) of ATC-40. )When equivalent linearization is used as a part of a nonlinear static procedure that models the nonlinear response of a building with a SDOF oscillator, the objective is to estimate the maximum displacement response of the nonlinear system with an “equivalent” linear system using an effective period, Teff, and effective damping, βeff (see Figure above). The global force-deformation relationship shown in the above figure for a SDOF oscillator in acceleration-displacement response spectrum (ADRS) format is termed a capacity curve. The capacity curve shown in the above figure is developed using the conventional procedures of FEMA 356 or ATC-40. The effective linear parameters are functions of the characteristics of the capacity curve, the corresponding initial period and damping, and the ductility demand, µ.