Prediction of physical and mechanical properties and influencing factors of larch wood in historic buliding
Historic wooden buildings having a long history in China,being a testament to the country's rich cultural heritage.In view of the preventive conservation of historic wooden buildings,it is important to predict and evaluate the properties of wooden components timely and effectively,which can be completed using non-destructive testing to assess the wood structural integrity of the building without any damage.In this study,non-destructive testing tech-niques like stress wave and micro-drilling resistance were combined with physical and mechanical properties testing in laboratory.The prediction equation of non-destructive testing parameters and physical and mechanical properties of larch wood was established,according to the progressive way of small specimens,reduced-scale specimens and full-scale specimens.Moreover,a field non-destructive testing and analysis method for the physical and mechanical prop-erties of larch wood in historic buildings was proposed.The results showed that,there was an obvious linear positive correlation between the wood density and the micro-drilling resistance in small specimens,and the correlation coeffi-cient of the linear equation between wood density and micro-drilling resistance was 0.91.However,the ultimate com-pressive strength,modulus of rupture and modulus of elasticity showed an obvious linear positive correlation with modulus of wave-resistance in small specimens.The correlation coefficients of the linear equations of ultimate com-pressive strength,modulus of rupture,modulus of elasticity and modulus of wave-resistance were 0.86,0.74 and 0.74,respectively.It was proved that the physical and mechanical properties of larch wood can be predicted by micro-drilling resistance and stress wave velocity test.Furthermore,there was a certain error in predicting the physical and mechanical properties of large specimens based on the prediction equation established by the test data of small speci-mens.The difference between predicted average value for density and compressive strength parallel to grain and the ac-tual average values were 12%and 16%to reduced-scale specimens,and the difference between predicted average val-ues for density and compressive strength parallel to grain and the actual average values were 16%and 17%to full-scale specimens.The testing path factors should be considered in the field testing for wood property,the density,compressive strength parallel to grain,and micro-drilling resistance value of larch wood all showed a gradual increase trend from the heartwood to the sapwood,and the external micro-drilling resistance value was 4%-16%larger than the overall micro-drilling resistance value.The full path micro-drilling test of the wooden component should be per-formed in the actual testing and evaluation,and if the full path micro-drilling test was limited by condition,the micro-drilling resistance value should be corrected on the basis of radial variation of different wood species.
historic buildingwooden componentlarch woodphysical and mechanical propertynon-destructive testing
万方数据
维普
