Analysis On The Degradation Of Mechanical Properties Of Damaged Timber Columns

The ancient buildings have a high value of culture,history and science.Many of the timber structures,which are historic,have been in service for centuries.However,wood is a natural biological material that is susceptible to erosion by natural and human factors.In the long years,the ancient timbe buildings accumulated different degrees of deformation and damage,component of the general existence of decay and moth and other local damage,the use of a significant decline in performance,structural safety.In this paper,the axial compression performance and repairing of the damaged timber columns were studied by means of experimental study.The mechanical properties degradation of the damaged timber columns were studied by numerical simulation and theoretical analysis.In this paper,localized trenching method was used to simulate the local damage of decay and insect moth on the timber columns.Eight square specimens with different size and position were designed and tested to research the effect of local damage on mechanical properties of timber columns.The experimental results show that the existence of local damage greatly weakens the mechanical performance of the timber columns,and the bearing capacity decreases with the increase of the width or length of the damaged area,and the position of the damage area is more favorable to the force of the members.The effect of the size and material of the stuffing block on the compression performance of the reinforced columns were studied by the axial compression tests.The results show that the effect of tampon reinforcement is better than that of the medium block with the size of the damaged area,and the repair effect of the hard wood is better than that of the original wood.The ABAQUS finite element software was used to simulate the wooden columns with different damage conditions in the above experiment.The simulation results were compared with the experimental results,and the feasibility of ABAQUS modeling was analyzed.O n the basis of this,considering the influence of the length,width and position of the damage area,the parameters of the damaged columns are enlarged.The results show that the finite element numerical simulation results are in good agreement with the experimental results.The finite element model established in this paper can simulate the real force of wood.Based on the analysis of the experimental phenomena and the finite element simulation results,the calculation model of the residual bearing capacity of the damaged wood column is deduced according to the stress mechanism and deformation characteristics of the damaged wood column.The calculated results are in good agreement with the experimental and finite element simulation results.