本文对意扬旋切板胶合木柱长期荷载作用下的蠕变性能开展了初步研究工作。试件为3组,尺寸均为150mm×150mm×2400mm,每组试件所施加的轴心受压荷载值都是根据先前相同尺寸柱短期轴压试验确定的。研究过程中用温湿度记录仪记录试验环境变化;用位移传感器记录试件中部的变形大小;运用黏弹性力学理论建立蠕变本构方程;利用Origin软件结合试验数据对本构方程的系数进行拟合。结果表明:足尺旋切板胶合木柱的蠕变变形由弹性变形、黏性变形和黏弹性变形组成;湿度和温度对蠕变变形的影响很大;通过Burger模型、三参量模型和经验模型建立蠕变本构方程,其中Burger模型与三参量模型能够较好地拟合本次试验曲线,而三参量模型所建立的本构方程能够更好地应用于实际工程中。
This paper studies the creep properties of full-scale poplar laminated veneer lumber column under the long term loading.The test specimens were divided into three groups, and all specimens were of the same size, which was 150 mm wide, 150 mm high, and 2400 mm long.The axial compressive load of each group was determined by the previous column axial compression test. During the experimental process, the environmental changes were recorded by the temperature and humidity recorders; the deformation of the middle part of the specimen was measured by the displacement sensor; the viscoelastic mechanics theory was used to establish the creep constitutive equations; the coefficients of the equation were fitted by Origin software combined with the test data.The experiment proved that the poplar laminated veneer lumber creep deformation was composed of elastic, viscous, and viscoelastic deformations. The influence of humidity and temperature on creep deformation was much greater.Based on the Burger model, the three parameter model, and the empirical model, the constitutive equation of creep was established. The Burger model and the three parameter model could fit the test curve well, while the constitutive equation established by the three parameter model could be better applied in practical engineering.