Practical techniques for the vibration method with additional mass: effect of crossers’ position in longitudinal vibration

The effect of the crosser’s position used for piled lumber on longitudinal vibration was investigated. As a model case, specimens with and without a concentrated mass were compressed in their thickness direction at nodal and antinodal positions of longitudinal vibration, following which, longitudinal vibration tests were conducted. Density and Young’s modulus were unaffected by compression of the specimen at the nodal position but was affected by compression at the antinodal position. By placing crossers at the nodal positions, accurate density and Young’s modulus values can be determined using the vibration method with additional mass without the influence of weight of the upper lumber.