竹帘胶合板夹板剪力墙的破坏模式及损伤评估  

Failure mode and damage assessment of the midply-bamboo shear walls

作　　者：夏天 周宇 郑维 董利 王志强 赵天长 XIA Tian;ZHOU Yu;ZHENG Wei;DONG Li;WANG Zhiqiang;ZHAO Tianchang(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;Jiangsu TigerWoods Construction Engineering Co.Ltd.,Nanjing 210012,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037 [2]江苏森之虎建筑工程有限公司,南京210012

出　　处：《林业工程学报》2022年第3期53-59,共7页Journal of Forestry Engineering

基　　金：江苏省自然科学基金(BK20180778);江苏省高等学校大学生创新创业训练计划项目(202010298073Y)。

摘　　要：竹帘胶合板(竹胶板)和自攻螺钉的使用有助于避免夹板剪力墙出现板边撕裂和钉子拔出等不利破坏,其对墙体破坏模式和损伤的影响值得深入分析。对考虑了墙肢长度、钉间距、竹胶板厚度等参数变化的4组竹胶板夹板剪力墙试件进行单调与低周往复加载试验,分析其破坏模式、抗侧刚度、极限承载力及端部墙骨柱的抗失稳能力,并采用基于能量的损伤模型对其进行损伤评估。结果表明,竹胶板夹板剪力墙在单调荷载作用下存在端部墙骨柱失稳破坏,实际应用中应通过拼合柱或增加封头墙骨的方式加以避免。在往复荷载作用下,竹胶板夹板剪力墙以螺钉疲劳剪断和顶梁板劈裂破坏为主,并因此表现出明显强度退化和残余变形。减小螺钉间距和增大墙体长度都可以显著提高竹胶板夹板剪力墙抗侧力性能,而改变中心夹板厚度则影响甚微。结合试验现象、损伤指数曲线和我国地震设防水准,将竹胶板夹板剪力墙的损伤分为4个等级:基本完好(损伤指数<0.2,对应小震)、轻微损伤(0.2≤损伤指数<0.55,对应中震)、严重损伤(0.55≤损伤指数<0.9,对应大震)、失效(损伤指数≥0.9,对应倒塌)。When subjected to lateral loads,midply shear walls fabricated with wood-based structural panels and common nails often fail in terms of sheathing tearing and nail withdrawal,which severely takes the edge off their lateral performance.As an alternative,the combined use of plybamboo panels and self-tapping screws can address the above-mentioned adverse failures.However,the effect of the new method on the failure modes and damage of the walls needs to be investigated.Four groups of midply-bamboo shear wall specimens were tested under monotonic and cyclic loading,considering varying wall length,screw spacing and middle-sheathing thickness.The failure modes,lateral stiffness and ultimate bearing capacity of the specimens were analyzed to evaluate the effect of these variables on the lateral performance of midply-bamboo shear walls.The Euler critical force of the end studs in the midply-bamboo shear walls were compared with the peak load calculated according to in-plane moment equilibrium equation of wood-frame shear wall,so as to predict the probability of end stud buckling.Damage assessment was performed in accordance with the energy-based damage model proposed by Kratzig.The results showed that the midply-bamboo shear walls under monotonic loading may failed in terms of buckling of the end studs,which should be avoided by increasing the cross-section of the end studs.Under cyclic loading,fatigue crack of the screws and splitting of the top plates were the two main failure modes of the midply-bamboo shear walls,leading to significant strength degradation and residual deformation.The ultimate bearing capacity of the 1.22 m midply-bamboo shear walls was quite close to that of the 2.44 m walls,signifying that the load-carrying capacity of midply-bamboo shear wall was proportionate to wall length.Decreasing screw spacing means more double-shear screw connections in midply-bamboo shear walls and could correspondingly improve the ultimate bearing capacity and lateral stiffness of the walls,whereas the thickness of middle p

关 键 词：夹板剪力墙 竹胶板 自攻螺钉 破坏模式 损伤评估 

分 类 号：S781.23[农业科学—木材科学与技术] TU366[农业科学—林学]