共查询到19条相似文献,搜索用时 234 毫秒
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椭圆榫过盈配合量与木材密度的关系 总被引:3,自引:0,他引:3
通过樟子松、柳桉、山毛榉制成的椭圆榫接合的极限抗拔试验,发现椭圆形榫头宽度与其对应的榫眼长度的过盈配合中,这三种木材在平衡含水率14.0%时的最佳过盈配合量分别为0.80、0.47和0.26mm.在此基础上,进一步探讨最佳过盈配合量与木材密度的相关性,得到其回归拟合曲线近似为指数函数y=6.874e-4.604x. 相似文献
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基于摩擦特性的榫接合节点抗拔力研究 总被引:1,自引:0,他引:1
《林业工程学报》2017,(4)
通过创新的测量方法对椭圆榫接合节点的摩擦特性进行了研究,基于合理的条件假设,建立了椭圆榫接合节点抗拔力的数学模型,并通过椭圆榫接合T形构件的抗拔力试验对模型计算结果进行了检验。研究结果表明,基于本研究所采用的加工方式,木材在平面接触状态下,接触面纹理角度、接触面积以及接触压力对木材与木材间的摩擦系数无明显影响。各接触面粗糙度测量结果表明,横纹不同纹理角度和顺纹不同纹理角度下的粗糙度基本相等。通过创新的试验方法对不同纹理角度的椭圆榫接合节点摩擦系数进行测量,其结果与平面接触状态下的测量结果基本一致,平均摩擦系数约为0.54。试验验证阶段对采用椭圆榫接合的T形构件抗拔力进行了测量,得到抗拔力平均值为3 192.5 N,标准差为398 N,而通过本研究建立的数学模型计算所得的榫接合节点抗拔力为2 928.08 N。数学模型计算结果与试验结果的最大值及最小值的误差均在标准差范围内。因此,本研究所建立的力学模型可用于实木椭圆榫接合节点抗拔力的估算,并为榫接合节点在胶合状态下的力学特性研究,以及实木榫接合家具结构设计提供依据。 相似文献
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为实现实木椭圆榫接合家具节点的可拆装性,提出一种通过五金连接件改良椭圆榫节点的方法,测试T型构件的抗拔及抗弯力学性能,并分析节点加载过程中的力学行为及失效形式。结果发现,较对照椭圆榫节点,改良五金件连接节点的极限抗拔承载力达到5 614.61 N,提升了230%,但破坏弯矩降低了48.6%,刚性系数降低了45.6%。在保留实木椭圆榫外观及可拆装设计的前提下,本研究设计的可拆装式椭圆榫节点能满足多数木制品节点的使用强度要求,为后续实木可拆装式椭圆榫节点的优化设计提供依据及方法。 相似文献
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为减少家具的质量波动并延长其使用寿命,将稳健设计思想引入板式家具的结构设计中,对以多层板为基材的板式家具T型构件,进行稳健优化设计。试验选取板式家具中最常见的连接件——圆棒榫为优化对象,通过田口法,研究圆棒榫的直径、长度、材料三个因素对18 mm厚多层板T型构件抗弯性能的影响。将抗弯极限承载力设为目标质量特性,信噪比(S/N)作为衡量产品质量稳定性的指标。结果表明:以多层板为基材的T型构件抗弯强度随圆棒榫直径和长度的增加而增强;三种材料中,荷木圆棒榫表现出最好的性能;圆棒榫直径对构件的抗弯性能影响最大。优化后,长为50 mm且直径为10 mm的荷木圆棒榫为最稳健设计方案。三种设计因素中,优化后板式T型构件的抗弯极限承载力增强21.07%,信噪比提高4.42%。试验表明:基于稳健设计原则的田口法可有效增强板式家具T型结构节点的质量稳定性,进而实现板式家具结构质量稳定性的提升,延长家具的使用寿命。 相似文献
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冷压制造结构用单板层积材时,单位压力、加压时间、陈放时间、涂胶量和胶种是影响其强度性能的重要因素,同时各因素的变化还直接影响到生产成本和生产效率。试验表明,理想的冷压工艺条件为:单位压力 0.98 MPa、加压时间 7 h、陈放时间 40 min、涂胶量 180g/m2(单面)。 相似文献
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为增强板式家具角接合强度,提高家具结构质量的稳定性,对以18 mm厚刨花板为基材的T型构件进行角接合强度稳健优化设计。选取圆榫直径(6、8、10 mm)、圆榫长度(30、40、50 mm)、连接件种类(二合一连接件、三合一连接件、四合一连接件)及连接件长度(35、40、45 mm)为设计因素,采用L9(34)正交表进行试验方案设计。使用ANSYA有限元软件,对构件进行模拟抗弯测试,将构件的形变量、连接件及圆榫的最大等效应力作为衡量指标,通过稳健设计田口法结合灰色关联分析法对板式T型构件角接合强度进行多指标稳健优化。结果表明:长40 mm的四合一连接件,配以长为30 mm,直径为8 mm的圆棒榫为本研究的稳健优化结果。选取各因素中间水平为初始对照组,优化后构件的形变量减少1.71 mm,连接件的等效应力减小207.94 MPa。虽圆榫的等效应力有所增加,但综合性能有所提升,灰色关联度由0.60增加至0.78,提高30%。试验证明:田口法结合灰色关联分析法可有效将板式家具研究中的多指标问题转化为单一问题进行研究,实现板式家具的稳健设计,进而实现家... 相似文献
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Finite element analysis of stress and strain distributions in mortise and loose tenon furniture joints 总被引:1,自引:0,他引:1
We studied the effect of loose tenon dimensions on stress and strain distributions in T-shaped mortise and loose tenon (M&LT) furni-ture joints under uniaxial bending loads, and determined the effects of loose tenon length (30, 45, 60, and 90 mm) and loose tenon thickness (6 and 8 mm) on bending moment capacity of M&LT joints constructed with polyvinyl acetate (PVAc) adhesive. Stress and strain distributions in joint elements were then estimated for each joint using ANSYS finite element (FE) software. The bending moment capacity of joints increased significantly with thickness and length of the tenon. Based on the FE analysis results, under uniaxial bending, the highest shear stress values were obtained in the middle parts of the tenon, while the highest shear elastic strain values were estimated in glue lines between the tenon sur-faces and walls of the mortise. Shear stress and shear elastic strain values in joint elements generally increased with tenon dimensions and corre-sponding bending moment capacities. There was consistency between predicted maximum shear stress values and failure modes of the joints. 相似文献
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在木家具结构设计中,特别是具有中国传统家具风格的实木家具结构设计中,木框角部斜角榫接合强度是人们既关注又无法回避的问题。抗拉强度和抗弯强度是衡量木框斜角榫接合性能高低的两个重要指标。笔者对三种常用的、易于机械加工的斜角榫接合试件的强度(抗拉强度,抗弯强度)进行了实验测定,并从各个方面对其进行比较、分析。研究结果表明:斜角榫接合形式,胶黏剂种类,加压时间等各个因子都不同程度地影响着木框角部接合的整体结构性能。单肩斜角明榫接合效果最好。 相似文献
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基于Abaqus有限元分析,对不同榫长的实木榫卯连接梁柱节点和榫长为75 mm的不同层数的正交胶合木(CLT)榫卯连接梁柱节点进行数值模拟,分析其受力状态并提取荷载-位移曲线,与使用金属连接件连接的梁柱节点承载力进行对比,探究将榫卯连接应用在现代木结构中的理论依据。研究表明:竖向荷载作用下,榫长75 mm的榫卯连接梁柱节点承载能力处于M8和M10螺栓连接梁柱节点的理论承载力之间;当榫长增大时,节点的最大承载力逐渐提高,榫长150 mm的榫卯节点承载力已经略微超过M12螺栓连接时的理论承载强度,说明榫卯连接梁柱节点在承载能力上可以满足现代木结构建筑的使用要求。由于榫卯节点的承载力主要受到顺纹抗压强度的影响,因此相比于实木连接榫卯节点,CLT榫卯节点的承载力无显著提高。 相似文献
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Strength performance of mortise and loose-tenon furniture joints under uniaxial bending moment 总被引:2,自引:0,他引:2
We determined the effects of adhesive type and loose tenon dimensions (length and thickness) on bending strength of T-shaped mor- tise and loose-tenon joints. Polyvinyl acetate (PVAc) and two-component polyurethane (PU) adhesives were used to construct joint specimens. The bending moment capacity of joints increased significantly with increased length and thickness of the loose tenon. Bending moment capacity of joints constructed with PU adhesive was approximately 13% higher than for joints constructed with PVAc adhesive. We developed a predictive equation as a function of adhesive type and loose tenon dimensions to estimate the strength of the joints constructed of oriental beech (Fagus orientalis L.) under uniaxial bending load. 相似文献
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Antonio Pantaleo Domenico Ferri Achille Pellerano 《Wood material science & engineering》2016,11(1):25-35
The research focuses on the assessment of the performances of glued laminated wood corner joints for outdoor window profiles applications, proposing a methodology to appreciate the strength of 90° tenon mortise corner joints. The rationale relies on the potential damage (i.e. breaking of the frame) that can be caused by poor glueing processes and/or typology of adhesives. There is a number of standards for assessment of wood-adhesive bonds for outdoor windows; however, there is a lack of specific standards related to glueing assessment for outdoor wood frames, which can take into account all the factors influencing the glueing quality. The proposed methodology was tested on red oak window profiles. A commercially available polyvinyl acetate-based adhesive was used for corner joints. Bending strength of 90° tenon mortise corner joints was measured and compared with maximum admissible loads on the frame to limit its deformations within admissible ranges. The test results show that the 90° tenon mortise corner joints strength exceeds the admissible load to preserve the functionality of the frame. In order to appreciate the influence of conditioning processes on adhesion, shear strength tests of the flatwise glued joint samples (bond lines of lamellae) were carried out after different conditioning processes. 相似文献
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J. Smardzewski 《Wood Science and Technology》2002,36(2):173-183
The current article presents an attempt to describe the strength of profile-adhesive joints. Its main objective was to develop
mathematical models describing phenomena occurring in bent mortise joints prevalent in constructions of skeleton furniture,
but also to determine factors influencing the strength of profile-adhesive joints. The presented cases of gluing of a mortise
joint reveal that mutual interactions of compressed wood surfaces influence significantly the strength of the developed node.
In extreme cases, when a glue bond fails to form on surfaces of elements, the strength of the joint will depend only on the
compression strength of wood. That is why, despite the impairment of the adhesive bond, the construction will still be able
to carry considerable outside loads. However, the best situation is when well fitted elements of the joint, compressing one
another, reduce stresses in the glue bond and increase its strength above the value of outside loads exceeding greatly the
shear strength of the glue.
Received 1 November 1999 相似文献
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木构建筑的榫卯结构作为我国传统文化的瑰宝,在现代建筑中应用广泛。笔者通过对现存木构建筑中榫卯的作用以及种类的分析,归纳了木构建筑中的几种常用的榫卯及其应用方式。通过查阅资料以及实地考察,分析了国内外建筑中榫卯的应用方法,归纳出榫卯结构在现代建筑的应用现状与发展前景。从榫卯的材料和结构方面出发,介绍了现阶段榫卯的创新发展现状,结合其在建筑中应用的方法与未来发展方向,提出了榫卯的创新方向及趋势。对榫卯进行应用分析并为未来的发展提供大致的方向,为今后榫卯的再设计奠定坚实的基础,有利于对其进行更好的传承和发展。 相似文献
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介绍一种用动态信号分析仪测定强化木地板榫接部位横向变形量大小的方法。该法主要通过采集电涡流传感器中前置器解调后的地板榫接部位变形时的低频信号值获得其实际变形量,并为检测其它种类地板的变形量参数提供参考。 相似文献