利用超高性能混凝土(ultra high performance concrete, UHPC)材料特性,提出一种针对预制拼装桥墩的重力灌浆构造,即采用UHPC灌浆并依靠立柱自身重力完成拼接的插槽式连接构造。为研究该形式桥墩的抗震性能,设计完成了三个桥墩的拟静力...利用超高性能混凝土(ultra high performance concrete, UHPC)材料特性,提出一种针对预制拼装桥墩的重力灌浆构造,即采用UHPC灌浆并依靠立柱自身重力完成拼接的插槽式连接构造。为研究该形式桥墩的抗震性能,设计完成了三个桥墩的拟静力试验,分别为整体现浇墩Z1、新型插槽式连接墩P1及现有“I型”连接墩P2,并采用OpenSees有限元软件做模拟分析,与试验结果对比分析。结果表明:三个桥墩的破坏形式一致,均为弯曲破坏;Z1墩与P1墩滞回曲线呈梭形,滞回环较为饱满,且相同位移加载循环下的滞回路径较为吻合,P2墩接口处钢筋与混凝土间黏结滑移影响较大,导致滞回环面积减小,桥墩整体滞回耗能能力降低;P1墩的耗能能力较Z1墩和P2墩分别提升7.0%、10.7%,呈现峰值荷载小、失效速率慢、极限位移大、滞回耗能多的骨架趋势。试验结果与有限元模拟结果较为吻合,抗震性能参数差幅在10.0%以内,新型插槽式连接墩可应用于实际工程。展开更多
With the development of two-stage munitions(a precursor shaped charge(SC)and a following kinetic energy projectile)to attack the hard concrete targets,as well as the increasing applications of ultra-high performance c...With the development of two-stage munitions(a precursor shaped charge(SC)and a following kinetic energy projectile)to attack the hard concrete targets,as well as the increasing applications of ultra-high performance concrete(UHPC)in both civil and military protective structures,a comparative study on the impact performance of SC formed jet on UHPC target is performed experimentally and numerically at present.Firstly,a series of jet penetration/perforation test on the UHPC,45# steel and UHPC/45# steel composite targets are conducted.By assessing the penetration depth and borehole(crater and tunnel)diameter,the influences of target material and configuration as well as the standoff distance of SC on the impact performance of jet are experimentally discussed.Then,by adopting the 2 D multi-material Arbitrary Lagrange-Euler(ALE)algorithm,Fluid-Structure Interaction(FSI)method and erosion algorithm implemented in the finite element code LS-DYNA,the formation and impact performance of jet in the present test are well reproduced.Finally,based on the validated numerical algorithms,constitutive models and the corresponding parameters,the influences of target material(UHPC,NSC and 45# steel),standoff distance,target configuration(stacked and spaced)and weight efficiency on the impact performance of jet are further discussed.The derived conclusions could provide helpful references for evaluating the ballistic performance of jet and designing the protective structures.展开更多
文摘利用超高性能混凝土(ultra high performance concrete, UHPC)材料特性,提出一种针对预制拼装桥墩的重力灌浆构造,即采用UHPC灌浆并依靠立柱自身重力完成拼接的插槽式连接构造。为研究该形式桥墩的抗震性能,设计完成了三个桥墩的拟静力试验,分别为整体现浇墩Z1、新型插槽式连接墩P1及现有“I型”连接墩P2,并采用OpenSees有限元软件做模拟分析,与试验结果对比分析。结果表明:三个桥墩的破坏形式一致,均为弯曲破坏;Z1墩与P1墩滞回曲线呈梭形,滞回环较为饱满,且相同位移加载循环下的滞回路径较为吻合,P2墩接口处钢筋与混凝土间黏结滑移影响较大,导致滞回环面积减小,桥墩整体滞回耗能能力降低;P1墩的耗能能力较Z1墩和P2墩分别提升7.0%、10.7%,呈现峰值荷载小、失效速率慢、极限位移大、滞回耗能多的骨架趋势。试验结果与有限元模拟结果较为吻合,抗震性能参数差幅在10.0%以内,新型插槽式连接墩可应用于实际工程。
基金supported by the National Natural Science Foundation of China (51438003,51878507)
文摘With the development of two-stage munitions(a precursor shaped charge(SC)and a following kinetic energy projectile)to attack the hard concrete targets,as well as the increasing applications of ultra-high performance concrete(UHPC)in both civil and military protective structures,a comparative study on the impact performance of SC formed jet on UHPC target is performed experimentally and numerically at present.Firstly,a series of jet penetration/perforation test on the UHPC,45# steel and UHPC/45# steel composite targets are conducted.By assessing the penetration depth and borehole(crater and tunnel)diameter,the influences of target material and configuration as well as the standoff distance of SC on the impact performance of jet are experimentally discussed.Then,by adopting the 2 D multi-material Arbitrary Lagrange-Euler(ALE)algorithm,Fluid-Structure Interaction(FSI)method and erosion algorithm implemented in the finite element code LS-DYNA,the formation and impact performance of jet in the present test are well reproduced.Finally,based on the validated numerical algorithms,constitutive models and the corresponding parameters,the influences of target material(UHPC,NSC and 45# steel),standoff distance,target configuration(stacked and spaced)and weight efficiency on the impact performance of jet are further discussed.The derived conclusions could provide helpful references for evaluating the ballistic performance of jet and designing the protective structures.
