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

可以观察到木质材料在蠕变试验中的反应随着载荷量和暴露条件的不同而变化，例如在一系列湿度和时间范围内。特别是湿度条件的变化会引起蠕变挠度的变化，这被描述为机械吸附变形。本研究的目的是研究具有机械接缝和弯矩传递接缝的梁的蠕变及其对力学吸附变形的影响。接缝的力学吸附挠度模型的预测可以表示为受控环境的蠕变(三参数模型)和由变化的环境引起的挠度之和。挠度-时间曲线响应于室内环境中湿度的变化。在加载后的早期阶段，与相对湿度变化相对应的挠度不是很明显，但在后期试验中观察到了稳定性。钉-板-钉-钉接头的力学-吸附变形特征很简单，即随着相对湿度的增加，挠度减小，而木质材料的总挠度随着相对湿度的降低而当结构木构件在低应力水平下应用时，水分循环的影响可能会很显著。

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.