Test Research On Nailed Joints Of MIDPLY Shear Wall In Light Wood Frame Constructions

The MIDPLY shear wall system was developed by Canadian researchers to adopt in multi-storey wood-frame buildings. According to the previous study, the MIDPLY shear wall system performs excellent under earthquake and wind load. In order to make clear the performance of the nailed joints of MIDPLY shear wall, Monotonic loading were applied to 18 groups of nailed joints specimens based on the joints configuration, load to grain direction, panel type. Analysis of characteristic value was conducted to the test result. Moreover, theoretical value was calculated and compared with the test value. The results were as follows.(1) Devices to manufacture the test specimens of MIDPLY nailed joints and test the strength of wooden structure connection were developed.(2) The failures of standard nailed joints were mainly the nails pull through panels and the splitting of studs. The failures of MIDPLY nailed joints were mainly nails tore panels and nails bent and withdrew from the studs.(3) Maximum load, yield load, initial stiffness, ductility factor, energy dissipation of MIDPLY nailed joints loaded perpendicular to grain was respectively 76.0%,52.9%,222.9%, 59.8%,42.8% larger than that of standard nailed joints using the same sheathing panels. With the thickness of panel increasing, the bearing capacity, stiffness, ductility of nailed joints specimens were improved. Changing the thickness of OSB, including 9mm,12mm,15mm, used in MIDPLY specimens, the ratio of the maximum load applied perpendicular to stud’ grain was 1:1.57:1.93. The bearing capacity of MIDPLY nailed joints used 12 mm thickness structural plywood was 37.5%,9.5% larger than the values of that used OSB, furniture plywood with the same thickness separately.(4) The bearing capacity calculated based on Johansen theoretical model was almost the same with the test results.