Study on Compression Damage Law of Cypress Under Different Temperatures

In order to accurately determine the crack initiation law of wood component during

damage and fracture and effectively evaluate the degree of wood damage, in this experiment, cypress components under different temperature environments were taken as the research object. It was used to in-situ detect the compression damage evolution of cypress components at different temperature by acoustic emission techonlogy and digital image system. By analyzing the change of acoustic emission parameters and the strain curve of the crack surface area, the crack initiation law and crack initiation load of wood at different temperatures were explored. The results showed that the decrease in ultimate mean load of cypress members at 120, 140, 160 and 180 ℃ were 16.2%, 6.8% and 66.4%, respectively; the load value corresponding to the acoustic emission parameter data and the DIC damage cloud diagram can be used to analyze that the crack initiation load of cypress component at the crack initiation stage is 125, 62, 40 and 32 kN respectively. It was show that the higher the temperature, the lower the ultimate load and cracking load of wood, and the temperature has significant effect on the mechanical degradation performance of wood.