Study On Reinforcement Of Flexural Members Based On Component Fuse

Fiber Reinforced Plastic(FRP)is one kind of materials with high performance,which has diverse advantages such as light weight,high strength and strong erosion resistance,etc.Numerous studies at home and abroad show that though the bearing capacity and stiffness of the FRP reinforced members are obviously improved,the ductility of the reinforced members is obviously reduced.Especially for prestressed FRP reinforced members,the ductility of specimens decreases obviously,and the failure modes of the structures have changed.In addition to this,the process of destruction is rapid without warning signs.For those shortcomings,the FRP reinforcement structure is restricted in promotion and application.This paper firstly puts forward the reinforcement design method,the component fuse design method,which based on component fuse to solve the problem that there is no sign before the brittle failure of reinforced members.To ensure the safety reserve of reinforced members in a reasonable range,the component fuse should be precisely designed.The component fuse design method is of great significance for the promotion of strengthening structure.This paper adopts the methods of theoretical derivation and finite element analysis,and the research results are as follows:1.Reinforcement design method based on component fuse theoryIn the condition of the explicit initial design parameters,material parameters and reinforcement methods,this paper puts forward the reinforcement design method,which determines the amount of fiber reinforced plastic and the prestress applied to the fuse part and the bearing part of the component respectively by reinforcing the members of bearing capacity basic safety reserves in the warning state and additional safety reserves in the bearing capacity ultimate state.And the calculation formula and calculation parameters of component bearing capacity are derived.2.Stress analysis of strengthening member with component fuseThrough the finite element model,simulation of additional member reinforcement fuse members is completed,and the results show that in warning loads,fuse parts reach its ultimate strength and failure,which is in accordance with the design,to achieve the early warning function.By analyzing the load-deflection curve of the members,the results show that the failure of the fuse part has little effect on bearing performance of thecomponents.And the stiffness of reinforced members have no obvious changes.Those proved that the component fuse reinforce method can ensure component normally loaded and used,besides the obvious damage symptoms when warning load.The theoretical results are in good agreement with the simulation results.3.Analysis of internal force redistribution of reinforcement members and analysis of safety reserve indexBy comparing the load-stress curve of steel and fiber reinforced plastic and deflection of the component's warning state,yield state and ultimate state,the simulation results show that the failure of the fuse part has little effect on the overall bearing capacity of the component.In contrast to the bearing capacity index,ductility index and equivalent safety reserve index of members with different reinforcement ratio,we can draw the conclusion that the reinforcement design method based on the component fuse theory is little affected by the reinforcement ratio of the original component.To ensure the safety reserve index of the reinforced members,when the component reinforcement ratio is too great,the improvement of design capacity is reduced.