SPF规格材蠕变特性研究

以轻型木结构建筑常用的SPF规格材为研究对象,采用简支梁中部集中加载的方式进行短期弯曲蠕变试验。结果表明:在不同试验条件下蠕变经过瞬态蠕变阶段、相对稳定蠕变阶段。试件在不同持续负载水平下的蠕变应变-时间曲线具有几何相似性,其曲线的形状和走向趋势大致相同。蠕变变形量和曲线上的跳跃点随着应力水平的增加有增大的趋势。相比于侧弯受力,平弯蠕变速率更大,承载强度损耗较大。

Study on Creep Properties of SPF Dimension Lumber

Taking the light wood frame construction commonly used SPF dimension lumber(pine)as the study object, authors of this paper carried out the short-term bending creep experiments. The creep test adopted the method of centralized loading in the middle of simply supported beam. The results showed that the creep deformation under different test conditions goes throuht transient creep stage and relatively stable creep stage. The creep strain-time curves of the specimens under different sustained loads are geometrically similar. The creep deformation and jump point on the curve tend to increase with the increase of stress level. Compared with side bending, the creep rate of flat bending is higher and the bearing strength loss is larger.