Seismic Response Analysis Of Human-Structure Interaction System Based On Multi-rigid Human Body Model

With domestic and foreign research on human-structure interaction model and interaction mechanism moving forward,it has become a consensus that people within structure can’t be simplified as additional mass,and the current seismic design code in China only considers the human-induced load as part of the live load,thus ignoring the human-structure interaction,this may underestimate the seismic response of structures.However,the existing human-structure interaction models primarily focus on singleperson and long-span structures such as bridges or decks,studies on the interaction between crowd and other types of structures are still very rare.Based on the four rigidbody human model,a crowd model which can be used to analyze the crowd-structure interaction is established to study the influence of the crowd-structure interaction on the seismic response of structure.The main research contents of this paper are as follows:(1)The existing simulation models of human walking process are improved.By simplifying human body into a four-link structure and analyzing the walking process of human,the dynamic model of human walking process was established,and the impact equation of swinging leg and ground was introduced into the gait planning process,which simplifies the iterative solution process of human walking trajectory.The ground contact force of the four rigid-body human model in a single walking cycle was compared with the single walking load model in Fourier series form,and the feasibility of the improved four rigid-body human walking model was verified.(2)The crowd model is established to analyze the crowd-structure interaction.Taking the crowd density as the core parameter of the crowd model,the randomness in the crowd speed,the average step frequency and the synchronous rate was considered be to influenced by the crowd density.Then,accounting for the distribution law of each person’s mass,step frequency and phase,the Monte-Carlo method was used to obtain the mass,step frequency and phase of each person.Based on the four rigid-body human walking model,the movement process of each person in the crowd was simulated,and the feasibility of the model was verified from the crowd load.(3)The influence of crowd-structure interaction on crowd load and dynamic response of structure is analyzed.Based on the crowd model established in this paper,the crowd-structure interaction is regarded as the change of contact force between each person in the crowd and structure,and the crowd-structure interaction model is established within frame structure as the research object.This model is used to study the effect of structural vibration on crowd load and the effect of human-structure interaction on dynamic response of structure.(4)The effect of crowd-structure interaction and structure eccentricity caused by crowd gathering on seismic response of structure are studied.Taking the five-story steel-frame teaching building as the research object,the maximum inter-story drift ratio of the structure is calculated under different conditions,and the results are analyzed.The results show that considering the crowd-structure interaction and the structure eccentricity caused by the crowd gathering will increase the seismic response of the structure.