In this study,the dynamic response of an elastically connected multi-beam structure subjected to a moving load with elastic boundary conditions is investigated.The boundary conditions and properties of each beam vary,...In this study,the dynamic response of an elastically connected multi-beam structure subjected to a moving load with elastic boundary conditions is investigated.The boundary conditions and properties of each beam vary,and the difficulty of solving the motion equation is reduced by using a Fourier series plus three special transformations.By examining a high-speed railway(HSR)with mixed boundary conditions,the rationality for the newly proposed method is verified,the difference in simulated multiple-beam models with different beam numbers is explored,and the influence of material parameters and load speed on the dynamic response of multiple-beam structures is examined.Results suggest that the number of beams in the model should be as close to the actual beam number as possible.Models with an appropriate beam number can be used to describe in detail the dynamic response of the structure.Neglecting the track-structure can overestimate the resonant speed of a high-speed railway,simply-supported beam bridge.The effective interval of foundation stiffness(EIFS)can provide a reference for future engineering designs.展开更多
近年来,执行电梯安全功能的可编程电子安全部件〔Programmable electronic systems in safety-related applications for lifts (elevators)--以下简称PESSRALJ已经成为电梯控制技术开发和应用的热点。在电梯领域开发PESSRAL器件的标准...近年来,执行电梯安全功能的可编程电子安全部件〔Programmable electronic systems in safety-related applications for lifts (elevators)--以下简称PESSRALJ已经成为电梯控制技术开发和应用的热点。在电梯领域开发PESSRAL器件的标准、流程以及技术方法可以简单概括如下两种方式:(1)方式一。①依据GB 7588-2003《电梯制造与安装安全规范》确定PESSRAL所需执行的安全功能确认所需的安全完整性等级(Safety Integrity Level,以下简称 SIL),②依据 GB/T 20438-2017《电气/电子/可编程电子安全相关系统的功能安全》完成安全完整性设计(安全功能要求、安全状态要求、失效控制措施选取,PFH, SFF、HFT的计算以及SIL验算)。展开更多
基金Supported by:National Natural Science Foundations of China under Grant Nos.U1934207 and 51778630the Hunan Innovative Provincial Construction Project under Grant No.2019RS3009+1 种基金the Innovation-driven Plan in Central South University under Grant No.2020zzts159the Fundamental Research Funds for the Central Universities of Central South University under Grant No.2018zzts189。
文摘In this study,the dynamic response of an elastically connected multi-beam structure subjected to a moving load with elastic boundary conditions is investigated.The boundary conditions and properties of each beam vary,and the difficulty of solving the motion equation is reduced by using a Fourier series plus three special transformations.By examining a high-speed railway(HSR)with mixed boundary conditions,the rationality for the newly proposed method is verified,the difference in simulated multiple-beam models with different beam numbers is explored,and the influence of material parameters and load speed on the dynamic response of multiple-beam structures is examined.Results suggest that the number of beams in the model should be as close to the actual beam number as possible.Models with an appropriate beam number can be used to describe in detail the dynamic response of the structure.Neglecting the track-structure can overestimate the resonant speed of a high-speed railway,simply-supported beam bridge.The effective interval of foundation stiffness(EIFS)can provide a reference for future engineering designs.
