基于次应力分析的钢桁架节点连接计算

Calculation of Steel Truss Node Connection Based on Secondary Stress Analysis

本文介绍某项目钢桁架的相关计算问题,着重介绍全部由焊接箱型钢焊接而成的桁架在设计中的次应力问题;通过分析次应力产生的原理,结合《钢结构设计标准》(GB50017-2017)8.5节计算次应力效应公式,深入分析该类型桁架次应力跟主应力占比的分布规律;桁架杆件按拉弯或者压弯构件验算跟考虑塑性应力重分布等有利情况验算下两者应力对比分析。结果表明,现行软件按拉弯和压弯构件计算,截面偏保守,富裕度大,可考虑应力重分布来适当优化截面,而不降低结构的安全度,以供设计参考。

This article introduces the calculation problems related to a certain project's steel truss,with a focus on the secondary stress problem in the design of trusses welded entirely with welded box steel.By analyzing the principle of secondary stress generation and combining with Section 8.5 of the"Design Standards for Steel Structures"(GB50017-2017),the secondary stress effect formula is calculated.The distribution law of the proportion of secondary stress to main stress in this type of truss is deeply analyzed.The stress comparison analysis between truss members calculated based on tension bending or compression bending components and considering favorable conditions such as plastic stress redistribution shows that the cross-section is conservative,and margin is large with current software calculating based on tension bending and compression bending components.Stress redistribution can be considered to appropriately optimize the cross-section without reducing the safety of the structure,provided for design reference.