地震作用下空间网架结构考虑损伤累积效应的弹塑性分析
|
摘要
考虑钢材的损伤累积效应和应变强化效应,应用塑性应变和能量耗损理论建立了钢材的损伤力学模型;在此模型基础上,推导了网架结构考虑损伤累积效应的单元弹塑性刚度矩阵和结构动力平衡微分方程,编制了相应的有限元分析计算程序,并对一空间网架结构算例进行了数值仿真分析。结果表明,考虑损伤累积效应对空间网架结构的弹塑性地震反应有着显著的影响,其中有损伤杆件的应力减小、应变增大;无损伤杆件的应力、应变均增大;在不同方向组合地震的作用下,考虑与不考虑损伤累积效应,网架结构的内力和变形趋势相同;不同的地震作用,考虑损伤累积效应时对网架结构的内力和变形的影响也较大。
A damage model of steel is built on the basis of the theory of plastic strain and energy dissipation, in which the damage accumulation effect and the strain strengthening effect are considered. With this model, the elasto-plastic element stiffness matrices and the structural dynamic equilibrium equations of spatial trusses are derived. The corresponding computing program of the finite element analysis is developed, and the numerical simulation of an example truss is carried out. Numerical results show that the elasto-plastic seismic responses of the spatial trusses are significantly affected by the damage accumulation effect. The stresses of the damaged rods increase and its strains decrease, but both stresses and strains of the undamaged rods increase. Under the combined excitations of the earthquakes in different directions, the variational tendency of the internal forces and deformations of the truss is the same and irrelevant to the damage accumulation effect. Under the excitations of different earthquakes, the damage accumulation effect on the internal forces and deformations of the truss is also significant.
A damage model of steel is built on the basis of the theory of plastic strain and energy dissipation, in which the damage accumulation effect and the strain strengthening effect are considered. With this model, the elasto-plastic element stiffness matrices and the structural dynamic equilibrium equations of spatial trusses are derived. The corresponding computing program of the finite element analysis is developed, and the numerical simulation of an example truss is carried out. Numerical results show that the elasto-plastic seismic responses of the spatial trusses are significantly affected by the damage accumulation effect. The stresses of the damaged rods increase and its strains decrease, but both stresses and strains of the undamaged rods increase. Under the combined excitations of the earthquakes in different directions, the variational tendency of the internal forces and deformations of the truss is the same and irrelevant to the damage accumulation effect. Under the excitations of different earthquakes, the damage accumulation effect on the internal forces and deformations of the truss is also significant.
引文
[1]沈为.损伤力学[M].武汉:华中理工大学出版社,1995.ShenWei.Damage mechanics[M].Wuhan:HuazhongUniversityPress,1995.(inChinese)
[2]沈祖炎,董宝,曹文衔.结构损伤累积分析的研究现状和存在的问题[J].同济大学学报,1997,25(2):135-139.ShenZuyan,DongBao,CaoWenxian.The state-of-the-art on damage cumulation analysis of building structures[J].Journal ofTongjiUniversity,1997,25(2):135-139.(inChinese)
[3]尹双增.断裂、损伤理论及应用[M].北京:清华大学出版社,1992.YinShuangzeng.Theory andApplication ofFracture andDamage[M].Beijing:TsinghuaUniversityPress,1992.(inChinese)
[4]ShenZ Y,DongB.An experiment-based cumulative damage mechanics model of steel under cyclic loading[J].Advances inStructuralEngineering,1997,1(1):39-46.
[5]SatoshiIwai,Yeon-SooPark,TaijiroNakata,HiroyukiKameda,Very low-cycle fatigue tests of steel angle members under earthquake loading[C].Proceedings of the tenthWorldConference onEarthquakeEngineering,1992.2879-2884.
[6]Lemaitre,J CbabocheJ L.Mechanics ofSolidMaterials[M].London:CambridgeUniversityPress,1990.
[7]郑宏,俞茂宏,顾强.结构钢损伤本构关系的研究[J].计算力学学报,2001,18(4):469-472.ZhengHong,YuMaohong,GuQiang.On constructional steel damage constitutive relations[J].ChineseJournal ofComputationalMechanics,2001,18(4):469-472.(inChinese)
[8]ChowC L,WangJ.Continuum damage mechanics model for crack initiation in mixed mode ductile fracture[J].InternationalJournal ofFracture,1991,47(2):145-160.
[9]KumarS,UsamiT.A note on evaluation of damage in steel structures under cyclic loading[J].ASCE,J StrucEng,1994,40A:177-188.
[10]GuptaV K,NielsenS R K,KirkegaardP H.A preliminary prediction of seismic damage-based degradation inRC structures[J].EarthquakeEngineering andStructuralDynamics,2001,30(7):981-993.
[2]沈祖炎,董宝,曹文衔.结构损伤累积分析的研究现状和存在的问题[J].同济大学学报,1997,25(2):135-139.ShenZuyan,DongBao,CaoWenxian.The state-of-the-art on damage cumulation analysis of building structures[J].Journal ofTongjiUniversity,1997,25(2):135-139.(inChinese)
[3]尹双增.断裂、损伤理论及应用[M].北京:清华大学出版社,1992.YinShuangzeng.Theory andApplication ofFracture andDamage[M].Beijing:TsinghuaUniversityPress,1992.(inChinese)
[4]ShenZ Y,DongB.An experiment-based cumulative damage mechanics model of steel under cyclic loading[J].Advances inStructuralEngineering,1997,1(1):39-46.
[5]SatoshiIwai,Yeon-SooPark,TaijiroNakata,HiroyukiKameda,Very low-cycle fatigue tests of steel angle members under earthquake loading[C].Proceedings of the tenthWorldConference onEarthquakeEngineering,1992.2879-2884.
[6]Lemaitre,J CbabocheJ L.Mechanics ofSolidMaterials[M].London:CambridgeUniversityPress,1990.
[7]郑宏,俞茂宏,顾强.结构钢损伤本构关系的研究[J].计算力学学报,2001,18(4):469-472.ZhengHong,YuMaohong,GuQiang.On constructional steel damage constitutive relations[J].ChineseJournal ofComputationalMechanics,2001,18(4):469-472.(inChinese)
[8]ChowC L,WangJ.Continuum damage mechanics model for crack initiation in mixed mode ductile fracture[J].InternationalJournal ofFracture,1991,47(2):145-160.
[9]KumarS,UsamiT.A note on evaluation of damage in steel structures under cyclic loading[J].ASCE,J StrucEng,1994,40A:177-188.
[10]GuptaV K,NielsenS R K,KirkegaardP H.A preliminary prediction of seismic damage-based degradation inRC structures[J].EarthquakeEngineering andStructuralDynamics,2001,30(7):981-993.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心