基于相似理论的冲击模型试验结果修正-钢管混凝土柱的研究  

Correction of impact model test results using the similarity theory-study on steel tube concrete columns

作　　者：郑刚 肖建春[1,2] 郭华 马克俭 邱芸[3] ZHENG Gang;XIAO Jianchun;GUO Hua;MA Kejian;QIU Yun(Research Center of Space Structures,Guizhou University,Guiyang 550025,China;Key Laboratory of Structural Engineering of Guizhou Province,Guizhou University,Guiyang 550025,China;Sinohydro Ninth Engineering Bureau Co.,Ltd.,Guiyang 550025,China)

机构地区：[1]贵州大学空间结构研究中心,贵阳550025 [2]贵州大学贵州省结构工程重点实验室,贵阳550025 [3]中国水利水电第九工程局有限公司,贵阳550025

出　　处：《振动与冲击》2024年第20期140-149,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(50978064);贵州省自然科学基金(黔科合基础[2017]1036);贵州省科技计划项目(黔科合平台人才-YSZ[2022]001);贵州省人民防空办公室(BCXZFCG2017-068CG)。

摘　　要：缩尺模型冲击试验是研究原尺寸钢管混凝土冲击性能的重要手段之一,由于在冲击作用下,受应变率效应的影响,钢管混凝土柱缩尺模型试验中材料的动力强度和原型结构的动力强度并不满足相似比关系,导致缩尺试验结果映射原型结构冲击性能时存在一定的误差。基于密度、几何尺寸、冲击速度量纲体系建立相似模型准则,建立了大尺寸钢管混凝土柱侧向冲击的1/2、1/4和1/8相似缩尺模型,同时利用Workbench/LS-DYNA软件建立圆钢管混凝土柱侧向冲击的有限元模型,在验证模型的有效性后,分别从钢材和混凝土应变率敏感方程出发,对动态屈服应力相似性进行分析,重新推导相似比系数以解决材料应变率效应对不同相似比模型冲击性能的影响。结果表明,在考虑材料动态屈服应力相似后,钢管混凝土柱缩尺模型映射原尺寸结构冲击性能时,接触力、最大变形、屈服应力、冲击物速度和时间历程曲线吻合度的误差均得到进一步减小,其中最大变形误差减小最为显著,最大变形误差均在1.5%以内。总之,考虑材料动态屈服应力相似后,钢管混凝土柱缩尺模型映射原尺寸结构冲击性能的误差得到有效减小。Scaled model impact tests are essential for assessing steel pipe concrete’s impact resistance in its original proportions.The material’s dynamic strength and the prototype structure’s dynamic strength in the scaled model experiments of the steel pipe concrete columns do not satisfy the similarity ratio relationship due to the influence of the strain rate effect under impact.This causes a degree of error when the results of the scaled experimental model are extrapolated to the impact performance of the prototype structure.Based on the density,geometry,impact velocity dimension system,1/2,1/4,and 1/8 scaled-down models for the lateral impact of large steel-tube concrete columns were created.The Workbench/LS-DYNA software created a finite element model to simulate the lateral impact of a circular steel pipe concrete column.After confirming the model’s accuracy,the dynamic yield stress similarity was analyzed using steel and concrete strain rate-sensitive equations.Subsequently,the similarity ratio coefficients were recalculated.The results indicate that by taking into account the similarity in dynamic yield stress of the materials,the errors in contact force,maximum deformation,yield stress,impact velocity,and time course curve agreement of the scaled-down model of steel-pipe concrete columns,which reflect the impact performance of the original-size structure,were further minimized.Notably,the maximum deformation errors were significantly reduced,with all errors falling within 1.5%.In conclusion,the similarity of the materials’dynamic yield stress reduces the scaled-down model for steel-tube concrete columns’error in presenting the original-size structure’s impact performance.

关 键 词：钢管混凝土 应变率效应 相似比 冲击 

分 类 号：TU398.9[建筑科学—结构工程]