Abstract: [Objective] This research aims to investigate the bearing performance of domestic dimension lumber joints connected with domestic truss plate, and to offer a reference for the development and utilization of domestic building materials.[Method] Larix kaempferi dimension lumber harvested from Dagujia Forest Farm of Qingyuan Country, Liaoning Province, and domestic truss plates were selected as the experimental materials. The lateral resistance of teeth in four conditions was tested, with five repeated specimens for each condition. The shear strength in ten conditions was tested, with three specimens for each condition. The bearing capacity of L. kaempferi joints connected by truss plates under different working conditions were investigated and compared with imported truss plates and imported SPF dimension lumbers.[Result] The result shows that lateral resistances of teeth under conditions of AA, AE, EA, EE are 3.50, 2.53, 2.61 and 2.37 N·mm^-2,respectively. The strength of imported M20 truss plate is slightly lower than that of domestic truss plate under the EA working condition.While show 10.57%, 21.34%, 9.28% higher, respectively, under circumstances of AA, AE, EE by comparing the result of the two samples, which are L. kaempferi joints connected by domestic truss plates and those by import truss plates. On the other hand, the lateral resistances of teeth tested with import M20 truss plates connected by L. kaempferi are 36.27%, 50.49%, 30.00% and 40.00% higher than those by SPF under the four working conditions of AA, AE, EA, EE,respectively. The shear strengths of plate are 132.39, 122.73, 135.66, 199.13, 92.26, 172.76, 99.81, 89.52, 79.10 and 85.68 N·mm^-1 respectively under working conditions of θ=0°, θ=90°, θ=30° T, θ=60° T, θ=120° T, θ=150° T, θ=30° C, θ=60° C, θ=120° C as well as θ=150° C. The strengths of domestic truss plates connected with L. kaempferi are higher than those of imported truss plates connected with SPF except one when tested under θ=120° with shearing and tension.[Conclusion] The failure modes are identical for lateral resistance of teeth under four conditions,which was pulling out of the teeth.For shear strength test,the failure modes are splitting of dimension members at the abutting area,pulling out of teeth at the end of truss plate and warping of truss plate.Loading direction has significant impact on the bearing capacity of the truss plate joints.Compared with the imported truss plate connected SPF joints with, the load carrying performance of domestic truss plate connected Larix kaempferi joints with is better. Further research on L. kaempferi wood trusses connected with domestic truss plates may provide a scientific basis for development of Chinese wood structure system.

Key words: Larix kaempferi, domestic truss plate, ultimate lateral resistance of teeth, shear strength of truss plate