Modern factory automation is enabling the economic production of timber building components with sophisticated integral mechanical joints. This paper investigates the governing compressive failure mechanisms of full-length integrally-jointed plywood box columns, and in particular seeks to understand the interaction between localized material knot defects, integral box joint capacity, and column strength. A new critical failure mechanism is identified based on experimental observations and numerical analysis of sections with varying sizes of knot defect, with column capacity governed by defect-induced transverse loading of integral box joints. Column capacity was shown to improve with localized joint strengthening in knot-defective regions, or with a defect-adaptive fabrication procedure that avoids identified defects during component plate machining. The new failure mechanism was also combined with prior understanding of plate buckling and pop-off failure mechanisms to propose an overall failure process for integrally-jointed plywood columns. Results from this paper can also inform development of other types of integrally-jointed thin-walled structures.

中文翻译：

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带结缺陷的整体连接胶合板柱的结构行为

现代工厂自动化使具有复杂整体机械接头的木材建筑构件的经济生产成为可能。本文研究了全长整体连接胶合板箱形柱的控制压缩破坏机制，特别是试图了解局部材料结缺陷、整体箱形连接能力和柱强度之间的相互作用。基于实验观察和对具有不同尺寸结缺陷的截面的数值分析，确定了一种新的临界失效机制，其中柱承载力由缺陷引起的整体箱形接头的横向载荷控制。通过在结缺陷区域进行局部接头加固，柱承载力得到改善，或采用缺陷自适应制造程序，避免在部件板加工过程中发现缺陷。新的失效机制还与先前对板屈曲和弹出失效机制的理解相结合，提出了整体连接胶合板柱的整体失效过程。本文的结果还可以为其他类型的整体连接薄壁结构的开发提供信息。