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作 者 ：史贵荣 孙立谔

期 刊 ：林业科学 1989年 25卷 4期 页码：354-359

关键词：木质层合板；动力蠕变；蠕变模型；

Keywords:Wood laminated board, Dynamic creep, Creep model,

摘 要 ：在非对称循环载荷作用下,木质层合板的动力蠕变行为和大多数木质材料的静力蠕变行为基本一致。截止循环加载10万次,四单元粘弹性模型对三种试件在不同应力水平下的17组实验数据,拟合效果良好,相关系数R²均在0.99以上。三单元模型的均方拟合误差随承载周次的增加约比四单元模型大1—5倍。一般而言,三单元模型只适应于描述蠕变实验的初始阶段。

Abstract:Under 3-point sustained, un-symmetrical cyclic loading at constant temperature (18℃) and humidity (45—65% rh) condition but at various stress level from 20% to 100%, a group of experiments has been carried out on the creep behavior of birch laminated boards (LB) with 3 types of distinct assembly, which are employed in gymnastic vaulting-board. Results show that dynamic creep curves of LB are much analogous to those of many wood materials under static load. Using an iterative least squares computer program written by ourselves, the dynamic creep curves based on 3-and 4-element rheological model have been fitted to the 17 sets of data from specimens. Until 10⁵ cyclings, the 4-element model always provides the better overall fit to the data, for which the multiple correlation R² is more than 0.99 at each condition. The 3-element model seems appliable within the duration of delayed elastic stage, i.e. the primary creep region, in general.

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