摘要
为研究双折线抗力模型对空爆荷载梁式构件振动位移的影响,提出了柔性、刚性两类梁式构件正向弹塑性振动及回弹阶段弹塑性振动的分析法。应用等效单自由度法建立了各阶段振动方程并依据不同的初始条件推导出了各阶段的理论解。采用此理论解和代表性塑性强化系数,开展了双折线抗力模型中不同塑性强化程度对两类梁式构件正向弹塑性振动及回弹阶段弹塑性振动位移的典型工况验证。研究结果表明:基于双折线抗力模型位移理论解的适用范围更广;随着双折线抗力模型塑性强化系数的增大,两类梁式构件的最大弹塑性位移、残余变形均逐渐减小,且残余变形降低程度高于最大弹塑性位移;塑性强化系数增大到一定程度,梁式构件回弹阶段将出现塑性振动位移,进一步降低残余变形,无塑性回弹位移的理想弹塑性抗力模型会高估空爆荷载下梁式构件的残余变形。
In order to study the influence of bilinear resistance model on the vibration displacement of beam members under air blast loading,both the theoretical elast-plastic displacement solutions of the flexible and rigid members in forward and rebound stages were deduced,respectively.According to the relationship between blast duration and elastic duration from static position to maximum elastic displacement for members,the vibration situations could be divided into elastic forced vibration,elastic free vibration,plastic forced vibration,plastic free vibration,elastic rebound and plastic rebound.The equivalent single degree of freedom method was used to establish the vibration equations of each stage and the theoretical solutions of each stage were derived for different initial conditions.The method of the general solution plus the special solution was applied to solve each differential equation.Based on the theoretical solutions and the representative plastic strengthening coefficient,the elastoplastic vibration displacements of two types of beam members under different plastic strengthening degrees in the bilinear resistance model were verified under typical calculation cases.The corresponding complete vibration curves were finished for comparative analysis.The influence of the degree of plastic strengthening on the vibration representative value was analyzed.The results show that the displacement theoretical solution based on the bilinear resistance model has a wider range of application.With the increase of plastic strengthening coefficient of the bilinear resistance model,the maximum elastic-plastic displacement and residual deformation of the two types of beam members decrease gradually,and the reduction degree of residual deformation is higher than that of the maximum elastic-plastic displacement.When the plastic strengthening coefficient increases to a certain extent,the plastic vibration displacement will appear in the rebound stage of the beam members,further reducing the residual deformation.Compared with th
作者
耿少波
陈佳龙
赵洲
牛艳伟
GENG Shaobo;CHEN Jialong;ZHAO Zhou;NIU Yanwei(Department of Civil Engineering,School of Science,North University of China,Taiyuan 030051,Shanxi,China;Research Center of Highway Large Structure Engineering on Safety,Ministry of Education,Chang’an University,Xi’an 710064,Shaanxi,China)
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2022年第10期137-149,共13页
Explosion and Shock Waves
基金
国家自然科学基金(51408558)
旧桥检测与加固技术交通运输行业重点实验室(长安大学)开放基金(300102212516)。
关键词
双折线抗力模型
空爆荷载
弹塑性位移
残余变形
bilinear resistance model
air blast loading
elastic-plastic displacement
residual deformation
