杨绿峰, 宋沙沙, 刘嘉达仁. 钢桁架结构稳定性与两层面强度优化设计研究[J]. 工程力学, 2020, 37(1): 207-217,256. DOI: 10.6052/j.issn.1000-4750.2019.03.0095
引用本文: 杨绿峰, 宋沙沙, 刘嘉达仁. 钢桁架结构稳定性与两层面强度优化设计研究[J]. 工程力学, 2020, 37(1): 207-217,256. DOI: 10.6052/j.issn.1000-4750.2019.03.0095
YANG Lu-feng, SONG Sha-sha, LIU Jia-da-ren. STABILITY AND OPTIMUM DESIGN OF TWO-LEVEL STRENGTH FOR STEEL TRUSSES[J]. Engineering Mechanics, 2020, 37(1): 207-217,256. DOI: 10.6052/j.issn.1000-4750.2019.03.0095
Citation: YANG Lu-feng, SONG Sha-sha, LIU Jia-da-ren. STABILITY AND OPTIMUM DESIGN OF TWO-LEVEL STRENGTH FOR STEEL TRUSSES[J]. Engineering Mechanics, 2020, 37(1): 207-217,256. DOI: 10.6052/j.issn.1000-4750.2019.03.0095

钢桁架结构稳定性与两层面强度优化设计研究

STABILITY AND OPTIMUM DESIGN OF TWO-LEVEL STRENGTH FOR STEEL TRUSSES

  • 摘要: 现行桁架结构优化设计方法难以同时满足构件和体系两层面强度需求。鉴于此,利用弹性模量缩减法研究建立了考虑稳定性影响的桁架结构两层面强度优化设计的改进均匀承载法。在桁架杆件的截面轴向强度中引入压杆稳定系数,据此建立考虑稳定性影响的桁架杆件单元承载比计算表达式。根据弹性模量缩减法迭代首步与末步的构件承载比分别确定桁架在构件和体系两个层面的强度系数,建立构件与体系两层面强度之间的显性关系式按照两层面强度系数的目标值调整各构件的截面强度,利用构件承载比均匀度建立桁架结构优化设计的迭代收敛判据。通过对比分析,验证了该文方法建立的结构设计方案,取得了较好经济效果,克服了现行桁架结构优化设计方法难以满足桁架两层面强度需求的缺陷。

     

    Abstract: The traditional truss optimal design methods can hardly satisfy the strength requirements at both component-and system-levels simultaneously. In order to overcome this problem, an improved method of uniform bearing criterion was proposed for the optimal design of two-level strength of steel trusses using the elastic modulus reduction method, considering the effect of structural stability. Firstly, the stability coefficient was introduced into the sectional compressive strength for components of steel trusses, so that the element bearing ratio was developed for elements of a steel bar under the influence of structural stability. Then, the strength coefficients at component-and system-levels were determined respectively, using the component bearing ratio in the first and last iterative steps of the elastic modulus reduction method. The relationship between the two-level strength coefficients was presented explicitly. Furthermore, each component strength was adjusted in terms of prescribed targeted two-level strength coefficients, while the convergence criterion was proposed for the trusses optimal design based on the uniformity of component bearing ratios. Finally, it was demonstrated that the proposed method obtained a design scheme for steel trusses with lower cost, overcoming the limitation that the traditional optimum methods cannot meet the requirement of two-level strength.

     

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