Mechanical properties of monodirectional Gutou mortise-tenon joints of the traditional timber buildings in the Yangtze River region

The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region.

Experimental study on seismic characteristics of typical mortisetenon joints of Chinese southern traditional timber frame buildings

The seismic characteristics of four typical mortise-tenon joints of Chinese southern traditional timber frame buildings were researched, including Yanwei mortise-tenon joint （including dropping Yanwei mortise-tenon joint）, Shizigutou mortise-tenon joint, Ban mortise-tenon joint and Mantou mortise-tenon joint. Experiments on thirteen specimens were carried out. Failure modes, hysteresis curves, skeleton curves and rotational stiffness were studied. The results provided a theoretical basis for seismic research, protection and maintenance of Chinese southern traditional timber flame buildings.

Effects of timber infill walls on the seismic behavior of traditional Chinese timber frames

This study investigates the enhanced effect of timber infill walls on the seismic behavior of traditional Chinese timber frames.Two 1/2 scaled traditional Chinese timber infill walls(TIWs),two 1/2 scaled timber frames with timber infill walls(TFTIWs)and one 1/2 scaled timber frame(TF)were fabricated and tested under low-cyclic reversed loading.The failure modes,strength,stiffness,and energy consumption capacity of the TIWs and the TFTIWs were obtained,and the effects of the TIWs on the seismic performance of the TFTIWs were investigated.The results showed that the TIWs can increase the stiffness and ultimate bearing capacity of the TF,up to 60%and 80%,respectively.The strength degradation coefficient of the TFTIWs was slightly higher than that of the TF when the inter-story drift ratio exceeded 0.02 rad,and the TIWs helped to mitigate the strength degradation of the TFTIWs.It was also found that the TFTIWs had a higher cumulative energy dissipation when compared with the TF(up to a 60%increase),indicating the TIWs had reasonably good energy dissipation capacity.When the TIWs generated a solid contribution to the carrying capacity and energy dissipation of the TF,the lateral drift thresholds were 1/100 and 1/43 of the column height,respectively.Furthermore,the TIWs and TFTIWs presented a good ductility,and the TIW could effectively reduce the pull-out amount of the tenon from the mortise of the TF;however,the TIWs had little influence on the stiffness degradation level or improvement of the ductility of the TF.

Physical and mechanical properties of Klainedoxa gabonensis with engineering potential

Adequate information is sparse for many tropical timbers on their engineering applications, which make their international promotion difficult. The physical and mechanical properties of Klainedoxa gabonensis Pierre ex Engl. （a lesserutilized species） and Entandrophragma cylindricum were compared. K. gabonensis contained more moisture with greater density at 12 % moisture content than E. cylindricum and had a tangential-radial ratio for swelling and shrinkage of 1.31-1.38 and 1.58-1.63, respectively, within acceptable thresholds for engineering/structural timbers. For K. gabonensis, shear parallel to grain was 32.2 ± 0.4-33.5 ±1 N mm^-2; compressive parallel to grain, 80.7 ± 1.4-90.6± 1 N mm^-2; modulus of rupture, 204± 4.0-214 ± 4.0 N mm^-2 and modulus of elasticity, 28,932 ± 664-29,493 ±822 N mm^-2. These properties were superior to those of E. cylindricum [（15.5 ± 0.9）- （15.6 ± 0.6）, （56.4 ± 4.5）-（63.6 ± 1.2）, （99.4 ± 4.7）- （121.3 ± 10.6）, and （9987.4 ± 207）-（10,051 ± 258） N mm^-2, respectively] and compared well with those of several traditional timbers for conslruction and furniture production. Its use would contribute to minimize pressure on the primary timbers in the forests and widen the raw material base for wooden products.