随着装配式建筑在我国的推广应用越来越广泛,装配式构件在爆炸荷载下的性能值得深入研究。利用LS-DYNA显示动力分析软件对PC柱在近爆荷载下的动力响应及破坏模式进行数值模拟分析。计算了PC柱在8 kg TNT爆炸当量,爆炸距离(TNT炸药中心...随着装配式建筑在我国的推广应用越来越广泛,装配式构件在爆炸荷载下的性能值得深入研究。利用LS-DYNA显示动力分析软件对PC柱在近爆荷载下的动力响应及破坏模式进行数值模拟分析。计算了PC柱在8 kg TNT爆炸当量,爆炸距离(TNT炸药中心至结构表面)为0.6 m,比例距离为0.3 m/kg^(1/3)动力响应,分析轴压比、混凝土强度等级、截面惯性矩以及箍筋、纵筋配筋率对PC柱抗爆性能的影响,并与普通RC柱进行了对比研究。研究发现,有无轴压比对PC柱的抗爆性能影响很大,存在轴压比的时,PC柱的侧向位移明显较小。提高混凝土等级,增大截面惯性矩以及增加纵筋配筋率均可提升PC柱抗爆性能,箍筋配筋率影响较小。在相同模拟工况下,RC柱与PC柱破坏形式有所不同,PC柱表现出了更好的抗爆性能。展开更多
We show theoretically that range of reflection bands and defect modes inside the band gap can be tuned by using a one-dimensional tilted photonic crystal (TPC) structure. A TPC structure is similar to the conventional...We show theoretically that range of reflection bands and defect modes inside the band gap can be tuned by using a one-dimensional tilted photonic crystal (TPC) structure. A TPC structure is similar to the conventional PC structure with the only difference that in this case alternate layers are inclined at certain angle in the direction of periodicity of the structure. In order to obtain the reflectance spectra of the proposed structure transfer matrix method (TMM) has been employed. From the analysis of the reflectance curve, it is found that 100% reflectance range can be varied and enhanced by using TPC structure for both (TE- and TM-) polarizations. The enhancement in reflection bands increases as the tilt angle increases for both the polarizations and hence the enlarged omni-reflectance bands are obtained. Further, we study the properties of the defect modes in TPC structure by introducing the tilted defect at the different tilt angle. The results show that defect modes (tunneling modes) can be tuned at different wavelengths by changing the tilt angle of the structure without changing other parameters. Finally, the effect of variation thickness of defect layers on the tunneling mode has been studied for both TPC and conventional PC structure. The proposed model might be used as a tunable broadband omnidirectional reflector as well as tunable tunneling or transmission mode, which has potential applications in the field of photonics and optoelectronics.展开更多
文摘随着装配式建筑在我国的推广应用越来越广泛,装配式构件在爆炸荷载下的性能值得深入研究。利用LS-DYNA显示动力分析软件对PC柱在近爆荷载下的动力响应及破坏模式进行数值模拟分析。计算了PC柱在8 kg TNT爆炸当量,爆炸距离(TNT炸药中心至结构表面)为0.6 m,比例距离为0.3 m/kg^(1/3)动力响应,分析轴压比、混凝土强度等级、截面惯性矩以及箍筋、纵筋配筋率对PC柱抗爆性能的影响,并与普通RC柱进行了对比研究。研究发现,有无轴压比对PC柱的抗爆性能影响很大,存在轴压比的时,PC柱的侧向位移明显较小。提高混凝土等级,增大截面惯性矩以及增加纵筋配筋率均可提升PC柱抗爆性能,箍筋配筋率影响较小。在相同模拟工况下,RC柱与PC柱破坏形式有所不同,PC柱表现出了更好的抗爆性能。
文摘We show theoretically that range of reflection bands and defect modes inside the band gap can be tuned by using a one-dimensional tilted photonic crystal (TPC) structure. A TPC structure is similar to the conventional PC structure with the only difference that in this case alternate layers are inclined at certain angle in the direction of periodicity of the structure. In order to obtain the reflectance spectra of the proposed structure transfer matrix method (TMM) has been employed. From the analysis of the reflectance curve, it is found that 100% reflectance range can be varied and enhanced by using TPC structure for both (TE- and TM-) polarizations. The enhancement in reflection bands increases as the tilt angle increases for both the polarizations and hence the enlarged omni-reflectance bands are obtained. Further, we study the properties of the defect modes in TPC structure by introducing the tilted defect at the different tilt angle. The results show that defect modes (tunneling modes) can be tuned at different wavelengths by changing the tilt angle of the structure without changing other parameters. Finally, the effect of variation thickness of defect layers on the tunneling mode has been studied for both TPC and conventional PC structure. The proposed model might be used as a tunable broadband omnidirectional reflector as well as tunable tunneling or transmission mode, which has potential applications in the field of photonics and optoelectronics.
