基于C语言的结构用集成材木梁抗弯刚度模型研究

Research on Bending Stiffness C Language Model of Structural Glulam Beam

基于平行轴定理,采用变换截面法建立结构用集成材木梁的抗弯刚度C语言可执行程序模型,并通过足尺木梁的抗弯力学性能试验验证模型的有效性。本试验根据木材抗弯弹性模量测定方法国家标准(GB/T1936.2—2009)中的相关要求,测定层板木材的抗弯弹性模量并将其导入C语言程序模型,得到梁体抗弯刚度的模型理论值。依据结构用集成材国家标准(GB/T 26899—2011)对木梁进行四点抗弯测试并实时采集梁体跨中挠度、荷载数据,得到梁体抗弯刚度的实测值。对比梁体抗弯刚度的模型理论值与实测值,得出其平均相对误差率为3.89%。结构用集成材木梁抗弯刚度模型的建立应充分考虑梁体自身的构造缺陷,以综合层板的力学性能变异性及尺寸效应等影响因素,合理引入修正系数,提高模型的准确度与适用性。

Based on parallel axis theorem, initially established bending stiffness C-language executive model of Glulam beam based on a transformed section method. Moreover, full-scale Glulam beams have been conducted bending mechanical performance test to verify the validity of model. Wood laminations have undergone bending test for determination of modulus of elasticity （MOE） based on the procedures outlined in GB/T1936.2-2009 standard. The theoretical value of bending stiffness based on C-language model of Glulam beams can be obtained by inputting the concerned parameters including MOE as mentioned above. All the Glulam beams are instrumented on the Shimadzu universal mechanical test machine and tested to failure in four-point bending with reference to the requirements prescribed in GB/T26899-2011 standard. The mid-span deflections and applied loads are collected for computing the experimental value of bending stiffness of Glulam beams. Comparing the theoretical value based on C-language model with experimental values of Glulam beams, the relative error rate is 3.89 percent. When it comes to the establishment of a bending stiffness model of Glulam beams, it is of great necessity for accuracy and applicability of bending stiffness model to take account of some influencing factors such as the structural defect, mechan- ical properties variability and size effect and rationally introduce coefficient of correction.