腹板横截面剪切弹性模量对木质工字梁静曲挠度的影响

Influence of Edgewise Shearing Modulus of Elasticity of Web on Static-Bending Deflection of Wood I-Beam

对竹大片刨花板(BW)、木质定向刨花板(OSB)和结构胶合板(SPly)的剪切性能和以其为腹板的3种木质工字梁(IB)静曲挠度的检测和分析结果表明:腹板横截面剪切弹性模量(MOES)与IB的静曲剪切挠度和静曲总挠度成负幂指数关系;腹板MOES的不足对IB静曲挠度的不利影响不容忽视;实际应用中应注意到IB的跨度对静曲剪切挠度的影响;具适当MOES的BW、OSB和SPly均可满足IB对静曲剪切挠度的要求。建议我国相关标准和规范增补或修改对腹板用木质结构板的MOES指标要求及其检测方法,以及对IB静曲挠度中静曲剪切挠度的控制指标及其实用性工程计算方法。

The shearing property of bamboo waferboard （BW） , wood oriented strand board （OSB） and structural plywood （SPly） and the static bending deflection of the I-beam （IB） webbed with those panels were tested respectively. The results showed that there was negative power exponent correlation between the web＇s edgewise shearing modulus of elasticity （MOEs） and either the shearing or the whole deflection in static-bending of the IB. Therefore, the unfavorable effect from the poor MOEs on the static bending deflection should not be neglected with the consideration of the span in structural application. Also it was identified that the BW, OSB or SPly with proper MOEs could meet the shearing requirement for the web. Conclusively, this paper proposed that the criteria indexes with the test method for MOEs of the structural panels for web manufacture and the bending deflection including the edgewise shearing deflection with the practical engineering calculation should be added into the corresponding Chinese national standards, or the relevant standards should be modified.