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1.
螺钉连接是木塑复合材料构件的一种重要的连接方式,它在反复拆装后能否保持其原用强度尚有待于研究.笔者通过对L型和T型木塑构件,经不同拆装次数的结构强度和握钉力试验,得出了拆装次数与木塑构件强度的基本关系.  相似文献   

2.
为配合有关标准的制定,对6种异型结构的耐水木塑地板进行了弯曲性能测试公式的推导,并按照实际常用的跨距进行了测试.结果表明:300 mm和400 mm两种跨距的弯曲挠度均加大,但后者最大承载能力较前者小;这两种跨距对抗弯强度测试值影响不大,但弹性模量测试值变化较大.在使用中还需结合最大承我力和弯曲挠度,来确定合适的跨距.  相似文献   

3.
笔者采用稳健设计的田口实验方法,通过对松木L型构件整体式单榫连接进行ANSYS有限元模拟力学分析,研究其节点连接中各个设计因素对其最大形变量的影响,并通过信噪比因素效应分析,确定出松木L型构件连接结构的优化设计方案。结果表明:当松木L型构件构成形式为90°直角横材搭纵材,节点连接方式为直角榫,截面尺寸为256mm~2,榫头长度26mm时,最大形变值比初始状态降低了35.11%,信噪比提高了13.71%。利用ANSYS有限元软件结合稳健设计的田口实验方法可以减低松木家具结构质量特性的不稳健性,提高结构节点设计的安全性.降低结构设计成本,延长家具结构的使用寿命。  相似文献   

4.
塑木复合材料作为一种新型材料,其螺钉连接能否沿用木材或人造板材料的连接方式尚有待于研究.而引导孔孔径是影响木材和人造板材螺钉连接强度的重要因素,本文通过对塑木复合材料的握钉力和L型构件结构强度的测试,得出塑木构件螺钉连接强度的最佳引导孔孔径.  相似文献   

5.
以速生桉木单板层积材为基材,榫接合连接、螺钉连接的L型构件为研究对象,通过对桉木层积材家具接合构件进行抗拉和抗弯力学性能试验,观察、分析8种不同榫接合方式对"L型构件"接合强度的影响。研究结果表明,榫接合强度与接合面积有关,接合面积大则接合强度高;桉木单板层积材本身强度对榫接合无影响;采用偏心连接件、倒刺螺母螺杆连接件的接合强度较低,接合部位不够牢固,在家具的使用过程中容易产生松动。  相似文献   

6.
以南方速生脱脂马尾松松木为基材,以"L"型和"T"型构件为基本构件形式,采用力学实验方法 ,对理想使用状态——即在外力垂直荷载匀速加载的作用下使构件节点发生破坏或变形,测试构件节点破坏强度值及其破坏或变形形式。实验针对8种不同框架节点接合方式(贯通直角单榫接合、不贯通直角暗榫接合、双圆榫接合、倒刺螺母连接件接合、双圆榫与倒刺螺母共同接合、三件式偏心连接件接合,以及45°双圆榫斜角接合和45°不贯通榫斜角接合)的接合强度进行测定。实验结果表明:(1)对于直角连接构件,采用贯通直角单榫接合时的节点接合强度最大;双圆榫与倒刺螺母共同连接的节点接合强度次之;然后强度值从高到低依次为双圆榫接合、倒刺螺母螺杆连接件接合、不贯通直角单榫接合,接合强度最小的是偏心连接件接合;(2)对于45°斜角连接构件,采用45°不贯通榫斜角接合的节点强度大于45°双圆榫斜角接合的节点强度;(3)在相同条件下,"T"型实木构件的节点接合强度总体上大于"L"型实木构件的节点接合强度。研究表明:节点处的基本构件形式("L"型或"T"型)、角部构件的连接形式(直角构件或斜角构件),以及节点的接合方式等都不同程度地影响着马尾松松木家具框架节点的接合强度。  相似文献   

7.
以现有木塑工厂生产配方为基础,通过改进配方,采用熔融共混方法对木塑复合材料的耐热性进行研究.结果表明:在原有木塑厂生产配方基础上,基体树脂聚乙烯回料用量减少15%,同时添加10%的共聚型聚丙烯新料和5%玻纤,工业化放大生产制得的木塑复合材料热变形温度从61℃提高到99℃;弯曲强度从25 MPa提高到32 MPa;冲击强度从3.5 kJ/m2提高到3.7 kJ/m2,且生产成本并未明显提高.  相似文献   

8.
再生聚丙烯/木粉复合材料性能研究   总被引:2,自引:1,他引:2  
研究木粉用量、PP-g-MAH相容剂、WBG晶型改性剂,对再生聚丙烯/未粉复合材料性能和结构形态的影响。试验结果表明:PP-g-MAH能增加木塑复合材料的相容性,提高木塑复合材料的性能;适量木粉能提高复合材料的拉伸模量、弯曲性能和热变彤温度,但材料的冲击强度和断裂伸长率有所降低。添加WBG晶型改性剂,能改善复合材料的晶体结构,提高材料的塑性。  相似文献   

9.
为探讨改性辐射松应用于实木家具几种连接方式节点的接合强度,以辐射松树脂材与真空热处理树脂材为基材,采用力学试验方法测定"T"型与"L"型构件节点的破坏弯矩并分析其破坏特征。结果表明:相同条件下,树脂材节点接合强度大于热处理树脂材,贯通直角单榫双圆棒榫普通三合一连接件,"T"型构件节点接合强度大于"L"型构件,改性辐射松节点接合强度在一定条件下接近优质木材的节点接合强度。改性辐射松木材可满足实木家具对节点接合强度的要求,具备制造中高档松木家具的可行性。  相似文献   

10.
研究了跨距、加载辊直径、支撑辊直径、试件长度、加载速度等因素对中密度纤维板静曲强度和弹性模量试验结果的影响。结果表明:跨距大小及加载速度的改变对测试结果的影响较为明显,跨距增大静曲强度和弹性模量测试结果减小,加载速度增加静曲强度和弹性模量测试结果增大;试件长度、加载辊直径、支撑辊直径的改变对测试结果无明显影响。  相似文献   

11.
In past years high priority was given to developing a seismic design for wood structures, including research on the response of wood structures to earthquakes. In this study a new type of portal frame with relatively large span was developed for the traditional Japanese wooden houses with large openings at the front to strengthen the structure. Stainless steel plates coated with zinc and glued with epoxy adhesives on laminated veneer lumber (LVL) members, composed of Douglas fir veneer and bonded with phenolformaldehyde resin, were used. The connection between the frame's beam and columns and between the columns and groundsills was mechanical, with bolts. The subject of this research was to analyze strength properties and failure behavior of glued LVL metal joints used as structural components and to evaluate the response of LVL portal frames under cyclic lateral loading. The results show that portal frames using glued LVL metal plates have a good multiplier for the shear walls and may be applied to traditional Japanese structures. The equivalent viscous damping provided good energy dissipation in the frames. The joints displayed good mechanical behavior during tests; moreover, the structures demonstrated high strength, stiffness, and ductility, which are necessary for a seismic design.Part of this paper was presented at the 47th annual meeting of the Japan Wood Research Society, Kouchi, April 1997; and at the 5th world conference on timber engineering. Montreux, Switzerland, August 1998  相似文献   

12.
周忠祥 《林产工业》2007,34(6):20-22
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   

13.
为了探究木质材料在大型建筑应用的可行性,以竹材为原料,利用层积热压组坯的方式制备长度为3 m和6 m的竹质方梁,对其进行四点抗弯测试,观察其在测试过程中的弯曲变形及破坏特征,分析弹性模量、静曲强度,根据其破坏形式分析竹质方梁结构及组坯方式对其抗弯性能的影响。结果表明:6 m竹质方梁弹性模量达10261.24 MPa,跨中竖向位移至86.97 mm而不破坏;3 m竹质方梁静曲强度达85.51 MPa。竹质方梁破坏均出现在弯曲的受拉面,且裂纹通过竹节处、胶合界面以及竹纤维排布方向蔓延,这与竹材本身结构特性有关。通过对3 m和6 m竹质方梁抗弯实验及分析,以期为竹质方梁在大跨度下的应用提供数据支撑。  相似文献   

14.
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   

15.
Semi-rigidness of the joint connections is one of the main characteristics of timber structures. The pin-joint assumption for the semi-rigid joint connections might be not conservative in the timber structural design. In this paper, structural analysis was conducted on a semi-rigid timber portal frame; the formulas were derived in terms of the internal force and the lateral stiffness, and the influence of the semi-rigid connections was discussed. Moreover, experimental tests were performed on three full-scale timber portal frames and five bolted timber connections to study the lateral performance of the frames and the moment resistance of the connections. For consistency, the connections from the portal frames and the connections for bending tests were of the same configuration. Finally, a calculation flowchart of the lateral performance on a semi-rigid frame was presented to verify the derived formulas and to show a framework of the lateral structural design process.  相似文献   

16.
坝陵河大桥是沪瑞国道主干线贵州省镇宁至胜境关高速公路主跨1088m的单跨吊悬索桥。西锚碇为隧道锚,该隧道锚为目前国内最大的隧道式锚碇。由于锚碇上端的明洞一侧有汽车荷载的作用,而另外一侧只有土压力的作用,为了验算结构的受力状况,建立三维模型,进行三维有限元分析。本次分析根据结构的空间尺寸建立计算模型,考虑明洞在最不利荷载工况组合作用下承受的最大内力,进行结构应力分析,并据此进行结构强度分析。  相似文献   

17.
基于ANSYS Workbench的汽车球笼式万向节有限元分析   总被引:1,自引:1,他引:0  
基于有限元方法对轿车中应用广泛的球笼式等速万向节进行接触分析,对万向节在有限元软件ANSYS Workbench中的材料属性设置、边界条件处理及接触设置等进行阐述;通过对万向节进行有限元接触分析。获得万向节的内外滚道应力接触情况,得出整个万向节的使用寿命和疲劳安全系数。分析结果表明,万向节最大应力位置出现在位于内外滚道内的钢球上,且钢球与内外滚道接触应力分布也不均匀,为提高万向节结构整体寿命,应该对这些部位进行表面强化处理或选用高强度材料。在受到变载荷工况下万向节安全系数大部分在5以上,而钢球、星形套和钟形壳安全系数较低。本文可为研究万向节在疲劳作用下的薄弱部位及万向节设计与改进提供参考依据。  相似文献   

18.
单元拼装式自平衡预应力钢结构构件加工与安装   总被引:2,自引:0,他引:2  
预应力钢结构是一种将预应力与钢结构相结合,通过施加预应力充分利用钢材弹性范围内强度的新型结构。本文提出一种全新的预应力钢结构,此结构的突出特点是拼装式自平衡体系,即在充分利用轴心受压杆件长细比较小时使杆件发生强度破坏,达到充分发挥钢材潜力的目的。因此,在保证结构受压杆件和受拉钢绞线强度的前提条件下,根据建筑结构节点更强的原则及为了考虑施工方便、结构安全、结构耐久性等因素,对于构件设计、制作、加工及安装等问题的探讨是十分必要的。本文讨论一种新型结构及实验模型的构件加工、安装及在实际工程中的应用设想。  相似文献   

19.
This study is aimed to evaluate whether lintel has structural effect because it has not been categorized as a structural member. This study experimentally evaluated the horizontal load-carrying capacity of post-beam timber frame structures with bi-linear model and energy dissipation mechanism. To evaluate the effect on horizontal performance of lintel which has been widely used as wall frame in Korean traditional post-beam structure, two frames were tested in different types. One had no lintel and the other one had lintel at the height of 800 mm, respectively. Cyclic loading tests were conducted for each frame according to the standard loading protocol. Frame which had lintel showed slightly higher stiffness. And it showed noticeably significant energy dissipation performance after yield point of the joint. And that leads to the conclusion that lintel has structural effect and it should be considered as an important factor when evaluating horizontal performance of the structure after yield point of the joint.  相似文献   

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