Several studies based on structural properties of plywood walls and wooden semi-rigid frames have been conducted. However, the complex behavior of a wooden semi-rigid frame composited with structural plywood has made it difficult to establish its structural design method. The wooden semi-rigid frame joint has the problem of displaying semi-rigid performance. Therefore, it is difficult to satisfy the necessary stiffness of 1/120 radian, which is the limit value of the deformation angle in the elastic design of buildings. In this case, it is possible to compensate for the initial stiffness by incorporating a structural wall into a wooden semi-rigid frame. In general, an independent wall framework is set up within a wooden semi-rigid frame. A plywood board is nailed onto this framework. If it can be nailed directly onto the columns of the semi-rigid frame, there is no need to place a post in the framework, and the designing process can be more cost-effective.
Due to the complex behavior of the wooden semi-rigid frame composited with structural plywood, the structural design method cannot be established. This study aims to clarify the properties of the wooden semi-rigid frame with structural plywood with tests and build its structural design method.
A wooden semi-rigid frame with a lag-screw-bolt (LSB) for the joints was used in this study. The structural properties of the semi-rigid frame with structural plywood were estimated by conducting static racking tests for four types of specimens. The four types of specimens were as follows: “Rigid” wooden semi-rigid frame; “Outside” wooden semi-rigid frame with a structural plywood wall nailed on the outside edge of the column; “Inside” wooden semi-rigid frame with a structural plywood wall nailed on the inside of the column; and “Wall-O” and “Wall-I” structural plywood wall only.
Nuts were used to fill the empty 20 mm. The structural models of these specimens were simplified. At the bottom of each LSB, load cells were installed to measure the tension side axial force.
We examined the following: the shear-rotational angle curves of the wooden semi-rigid frame of “Outside”, where “Inside” was determined from the supporting point reaction; the shear-rotational angle curves of the plywood wall of “Outside”, where “Inside” was found by taking the load-rotational angle curves of “Wall-O” or “Wall-I”. The tests showed that there is a certain difference in the shear-rotational angle curves subjected to the nail position.
