针对现有桥梁护栏存在的防护性能不足、大规模改造需求、复杂施工条件等挑战,提出了“强-弱结合、刚-柔协同”的功能梯度型超高性能混凝土-发泡聚苯乙烯(Ultra high performance concrete-Expandable polystyrene,UHPC-EPS)夹芯护栏体系...针对现有桥梁护栏存在的防护性能不足、大规模改造需求、复杂施工条件等挑战,提出了“强-弱结合、刚-柔协同”的功能梯度型超高性能混凝土-发泡聚苯乙烯(Ultra high performance concrete-Expandable polystyrene,UHPC-EPS)夹芯护栏体系,通过LS-Dyna数值仿真技术,模拟了该护栏在小型客车、大型客车、大型货车碰撞场景下的轨迹偏移规律与损伤演化过程,并与现浇混凝土护栏开展了大型货车冲击工况下的力学性能对比研究。结果表明:功能梯度型UHPC-EPS夹芯护栏兼具优异的车辆轨迹导向能力和运行稳定性调控性能,同时具有强抗穿透特性与便捷的后期修复优势;在大型货车冲击工况下,UHPC-EPS夹芯护栏的峰值撞击力较现浇混凝土护栏降低了约12%,峰值剪力降低了约35%;配套研发的标准化施工工艺采用工厂预制、现场装配、一次成型的快速部署,具有显著的工程适配性与产业化推广价值。展开更多
In this paper,a semi-discrete model based on peridynamics(PD)for engineered cementitious composites(ECCs)is applied to simulate the fracture behavior of functionally graded ECC(FGECC)beams.This is a new application of...In this paper,a semi-discrete model based on peridynamics(PD)for engineered cementitious composites(ECCs)is applied to simulate the fracture behavior of functionally graded ECC(FGECC)beams.This is a new application of PD in ECC.Prior to simulating the crack behavior,the convergence of the PD model for ECC is discussed and the appropriate horizon size 5 and nonlocal ratio m are obtained,i.e.,S=1.6 mm and m=4.In addition,when the bond strain exceeds the elastic limit,a damage variable is introduced into the model,and the model is validated using a simple numerical algorithm.Finally,the dynamic fracture behavior of a two-dimensional FGECC beam under four-point bending is investigated,and the effect of the initial crack location on the fracture behavior is analyzed.Simulation results show that the initial crack location can affect the crack propagation pattern,thereby enabling one to understand the dynamic fracture behavior of ECC structures and guide the engineering practice.展开更多
文摘针对现有桥梁护栏存在的防护性能不足、大规模改造需求、复杂施工条件等挑战,提出了“强-弱结合、刚-柔协同”的功能梯度型超高性能混凝土-发泡聚苯乙烯(Ultra high performance concrete-Expandable polystyrene,UHPC-EPS)夹芯护栏体系,通过LS-Dyna数值仿真技术,模拟了该护栏在小型客车、大型客车、大型货车碰撞场景下的轨迹偏移规律与损伤演化过程,并与现浇混凝土护栏开展了大型货车冲击工况下的力学性能对比研究。结果表明:功能梯度型UHPC-EPS夹芯护栏兼具优异的车辆轨迹导向能力和运行稳定性调控性能,同时具有强抗穿透特性与便捷的后期修复优势;在大型货车冲击工况下,UHPC-EPS夹芯护栏的峰值撞击力较现浇混凝土护栏降低了约12%,峰值剪力降低了约35%;配套研发的标准化施工工艺采用工厂预制、现场装配、一次成型的快速部署,具有显著的工程适配性与产业化推广价值。
基金the Natural Science Foundation of China(Nos.11872339,11472248)the Natural Science Foundation of Henan Province(No.182300410221).
文摘In this paper,a semi-discrete model based on peridynamics(PD)for engineered cementitious composites(ECCs)is applied to simulate the fracture behavior of functionally graded ECC(FGECC)beams.This is a new application of PD in ECC.Prior to simulating the crack behavior,the convergence of the PD model for ECC is discussed and the appropriate horizon size 5 and nonlocal ratio m are obtained,i.e.,S=1.6 mm and m=4.In addition,when the bond strain exceeds the elastic limit,a damage variable is introduced into the model,and the model is validated using a simple numerical algorithm.Finally,the dynamic fracture behavior of a two-dimensional FGECC beam under four-point bending is investigated,and the effect of the initial crack location on the fracture behavior is analyzed.Simulation results show that the initial crack location can affect the crack propagation pattern,thereby enabling one to understand the dynamic fracture behavior of ECC structures and guide the engineering practice.
