Design Evaluation of Creep and Mechano-sorptive Deformatic of Mechanical Joints

在蠕变试验中，可以观察到木基材料的反应随载荷和暴露条件的变化而变化，例如在一定的湿度和时间范围内。特别是变化的湿度条件引起蠕变挠度变化，如所述的机械吸附变形。本研究的目的是研究在gluiam和LVL中具有机械节点和传递弯矩节点的梁的蠕变及其力学吸附变形的影响。节点力学-吸附挠度模型的预测可表示为可控环境蠕变（3参数模型）与变环境挠度的总和。在室内条件下，偏转时间曲线随湿度变化而变化。在加载初期，相对湿度变化引起的挠度变化不明显，但在加载后期，通过实验观察到其稳定性。钉板连接和漂销连接的力学吸附变形特征很简单，即相对湿度的增加使挠度减小，而木基材料的总挠度随着相对湿度的降低而减小，许多报道都表明。当结构木材构件在低应力水平下应用时，水分循环的影响可能是显著的。

The reaction of wood-based materials in creep testing may be observed to vary with the amount of loadings and exposure conditions, such an in a range of humidities and periods. Especially changing humidity conditions causes creep deflection to vary, as described as mechano-sorptive deformation. The purpose of this research is to present creep and the effects of mechano-sorptive deformation of beams with machanical joints and moment transmitting joints in gluiam and LVL.The prediction of the mechano-sorptive deflection model of joints can be expressed as the sum of the creep of controlled environment (3-parameter model) and deflection resulted from the variable environment.The deflection-time curves responded to variations of humidity in room conditions. The deflection corresponding to changing relative humidity is not so clear during the early stages after loading, but in the latter stages stability was experimentally observed. The characteristic of mechano-sorptive deformation for nail-plate-joints and drift pin joints are simple, that is, increasing relative humidity causes the deflection to decrease, while the total deflections for wood-based materials desreased when relative humidity dectresed as shown in many reports. The effect of moisture cycling can be significant when structural wood members are applied at low stress levels.