Research On The Flexural Performance Of Integrated Lightweight Insulated Structural Wall Panels Using UHPC

This paper proposes an integrated wall panel structure with lightweight insulation structure using UHPC,taking into account the research and development status of lightweight insulation structure integrated wall panels at home and abroad.The integrated wall panel uses UHPC containing steel fibres as the main material,with an EPS core arranged inside to form an insulation system.The integrated wall panels have the advantages of light weight,high strength,good durability,excellent thermal insulation,tight connection between materials and easy construction.In the present project,five unreinforced integrated wall panels and one reinforced integrated wall panel are subjected to four-point bending loading tests,and the results are analysed and collated;on this basis,a numerical model of the integrated wall panel is established,and the accuracy of the model is verified by comparing the simulation with the test results.A theoretical study of the bending performance of this lightweight insulation structure integrated wall panel was carried out,and a calculation model for the cracking moment and ultimate bending moment of the wall panel was proposed.The results of the study provide reference for the future application and promotion of the lightweight insulation structure integrated wall panel in the "structure-structure integrated structure".The results of this research show that:(1)With the void ratio,core diameter and the presence or absence of reinforcement as test parameters,six integrated wall panels with UHPC for lightweight insulation structures were designed and subjected to four-point loading tests to specifically analyse the crack development and the final damage state of the integrated wall panels under bending loads.With reference to the experimental phenomena,a comprehensive analysis of the flexural performance of the integrated wall panel was carried out in terms of the load-span displacement curve,bearing capacity,ductility and strain of the integrated wall panel.The test results showed that the integrated wall panel with reinforcement has good ductility and high flexural bearing capacity,and that the void ratio and core material diameter have a certain pattern on the flexural bearing capacity of the unreinforced integrated wall panel.(2)The numerical simulation study of the proposed lightweight insulation integrated wall panel was carried out by the finite element simulation software LS-Dyna.On the basis of a good geometric model,a suitable material model and a contact model were selected,boundary conditions were defined according to the test conditions,then model calculations were performed and the corresponding results were obtained and compared with the test results.The accuracy of the model was verified to determine the feasibility of the finite element simulation of this structural form.(3)Based on the assumption of flat sections,the cracking moments of reinforced integrated wall panels were calculated using the direct and indirect methods based on the stress-strain relationship between UHPC and reinforcement.The ultimate bending moments of all integrated wall panels were calculated using the section method and the theory associated with laminated panels.It was found that both methods were suitable for the calculation of cracking moments,with the calculated ultimate moments using the theory related to laminated plates being closer to the measured values.