Restoring force behavior of asymmetric damaged mortise-tenon joints of ancient wooden buildings

• 1、Haidu College, Qingdao Agricultural University, Laiyang, Shandong 265200, China

Abstract：In order to study the restoring force behavior of damaged mortise and tenon joints in ancient wooden buildings, four mortise-tenon joints were designed in the present work, including three through-tenon joints with different levels damage and one through-tenon joints without damage. The moment-rotation hysteretic characteristics of the mortise and tenon joints was analyzed under low cyclic reversed loading test. Through the analysis of the stiffness degradation law and hysteresis rules, the the formula of the characteristic coefficient for the ancient wooden buildings asymmetric mortise-tenon joints was proposed. And then the characteristic curve of restoring force of asymmetric mortise-tenon joints in ancient wooden buildings which indicates its real stress state has been set up. The experimental results indicate that the shape of the hysteretic curve of the joints changes from "S" shape to the reverse "Z" shape with the increase of the damaged level, and the pinching effect gets gradually significant. The skeleton curves of though-mortise joints exhibit significant asymmetry in forward and reverse loading. Compared with the experiments results, the restoring force characteristic curve fits better. The comparison and analysis results showed that the established restoring force characteristic curves fit well, indicating a certain degree of adaptability of the restoring force characteristic curve.

Keywords： ancient wooden buildings degree of looseness through-tenon joints restoring force model restoring force model