选取具有不同结构参数的减震垫进行冲击实验.在此基础上,采用BP神经网络预测模型算法与SPSS多元线性回归方程拟合算法分别探究运动地板减震垫结构参数与反冲击力之间关系,通过冲击实验获取实验数据与两种算法结果对比.结果表明:BP神经网络预测模型算法得出的数据与实验结果较为接近;以反冲击力与体积占比代数和最小作为优化目标,应用BP神经网络预测模型算法对给定参数范围的减震垫进行反冲击力预测,获得最优结构参数,经实验证明优化后的减震垫具有良好的冲击载荷吸收性能.

采用自然光对比不同纤维含量木纤维/聚乳酸复合材料进行光照老化试验,对比经过不同时间光照后材料的弯曲性能以及拉伸性能的变化,分析光照时间对材料力学性能的影响.结果显示,加入木纤维后,复合材料的弯曲强度和拉伸强度均出现了先下降后上升的趋势,说明加入一定量的木纤维会对复合材料体系起到一定的增强作用;在受到一定时间的自然光照射后,纯聚乳酸材料和木纤维/聚乳酸材料的弯曲性能和拉伸性能均有显著降低,含有木纤维的复合材料强度降低较少.

聚乳酸是一种强度较高的聚酯类材料,其良好的降解性能在保证了其环保优势的同时,也对其物理力学性能产生一定影响.本研究将木纤维/聚乳酸复合材料置于水环境中进行水解处理,然后测试复合材料的力学性能.结果显示,将复合材料放置在水中一段时间后,复合材料的弯曲性能和拉伸性能都显著下降,木纤维含量越高,材料性能下降越明显.这说明水环境使聚乳酸分子链发生了水解反应,使材料性能下降;同时,木纤维的吸水膨胀和干燥收缩也使材料界面薄弱点增加,使材料性能有所下降.

介绍国家标准GB/T 20239-2015《体育馆用木质地板》的修订原则与内容,解释体育馆用木质地板各层材料的理化性能要求与技术指标、检测方法、施工及验收要求等内容修订依据,为标准的理解与应用奠定基础.

The authors summarized current test methods, including gas analysis, desiccator, extraction and chamber methods, of formaldehyde emissions from wood-based flooring products used in a ground heating system. Characteristics of formaldehyde quantitative test methods, including acetyl acetone, chromotropic acid and phenol reagent methods, were also compared. It was proposed that chamber and chromotropic acid methods were the most suitable for measuring formaldehyde emissions from wood-based flooring products used in a ground heating system. It is suggested that the equilibrium treatment conditions of the testing sample and parameters of the simulated ground radiant heating device in the chamber be determined according to actual environment temperature characteristics for ground radiant heating.

The effects of wood fibre (WF) size on isothermal and non-isothermal crystallization morphology and capacity of PLA in WF/PLA composites were investigated with differerntial scanning calorimetry (DSC) and polarising optical microscopy (POM).It was found that wood fibres with different size had different effects on the melting temperature,crystallinity and crystal growth rate of PLA in WF/PLA composites during isothermal crystallization process.The melting peak of PLA component shifted to higher temperature by increasing fibre size.The middle size WF (diameter =0.012-0.050 mm,length =0.3-4.0 mm) could promote heterogeneous nucleation of PLA,increased crystal growth rate and crystallinity of PLA in composites.But the large size WF (diameter=0.07-0.50 mm,length =2-10 mm) would hinder crystal growth,then reduce crystallinity.On non-isothermal crystallization phase the results show that proper WF size could increase the overall crystallinity,melting peak temperature and crystallization temperature.But the large size WF (diameter=0.07-0.50 mm,length =2-10 mm) is too big to promote crystal growth.POM shows WF as a sort of heterogeneous nucleating agent could promote nucleus forming at the WF surface and confirmed the large WF would hinder crystal growth.

介绍了《结构胶合板》国家标准的编制原则和依据,并对标准中的技术要求、力学性能指标及试验方法等技术内容的编制依据进行了说明;以国产落叶松结构胶合板为试验材料,验证标准规定的方法和技术指标的可行性和科学性.

首次通过足尺检测的方式对不同规格杨木单板层积材性能进行检测.分析试验方法和试件规格尺寸等因素对杨木单板层积材静曲强度、弹性模量、抗压强度和抗拉强度等力学性能影响.测试结果显示:杨木单板层积材试件的幅面宽度对于材料的性能影响较大,幅面越宽试件中出现的缺陷越多,性能越低.

通过分析使用频次与木质体育地板表面粗糙度系数Rz、Ra、Rq和光泽度系数之间的关系发现:实际使用频次对木质体育地板表面漆膜磨损程度的影响较大,地板表面粗糙度会随着使用频次的增加呈现先减小后增大的趋势,而地板表面光泽度则随着使用频次的增加而减小;地板表面的漆膜会随着使用频次的增加而变薄、脱落.根据试验结果,提出关于体育场馆木质体育地板的使用和企业在地板生产工艺方面的相关建议.

为促进国产落叶松结构胶合板在建筑领域的应用,参考了日本农林标准《日本农林胶合板标准-结构用胶合板》,对7种厚度落叶松结构胶合板的面外剪切强度和大试件弯曲强度进行检测,旨在提供准确的设计和施工技术参数.结果显示,7种厚度胶合板的面外剪切强度和大试件弯曲强度,超过日本标准要求的指标值.

通过对不同厚度落叶松结构胶合板力学性能的测试试验,首次给出了7种厚度落叶松结构胶合板面外剪切强度和大板弯曲强度性能,以及达到的力学性能的等级标准.

介绍了结构单板层积材国家标准的编制原则和依据,并对标准中的技术要求、力学性能指标及试验方法等技术内容进行了说明.

采用对比的方法,确定原料的质量和技术参数,研究网格芯轻体细木工板最佳构成及工艺技术,获取芯板与表板最佳复合工艺;进一步对网格芯轻体细木工板产品的物理力学性能进行研究及应用性能开发,确定产品最佳应用领域范围.

In this paper diversity factors of full scale poplar laminated veneer lumber mechanical properties eigenvalue had been tested , and diversity factors of the results had been analyzed on different production , load directions and sizes .

木质体育地板在我国应用发展较晚,对其表面涂饰材料及工艺的研究和开发也是近年来才得到国家及相关企业的重视;国家至今尚未正式颁布体育馆用木地板国家标准,国内相关检测机构对于木质体育地板漆膜性能等方面的检测手段和设备也尚不完善,因此生产企业以及市场上用于体育馆木地板表面涂饰材料的种类和产品质量并没有统一的规范,产品的品种较多,性能差异也较大[1-2].

我国2002年和2003年颁布实施的GB 50206-2002《木结构工程施工质量验收规范》和GB/T50329-2002《木结构试验方法标准》及GB 50005-2003《木结构设计规范》3个木结构建筑标准规范,标志着木结构建筑将在我国重新得到认可、重视和推广应用.同时也进一步促进和拉动了我国结构用木质材料生产和加工技术及性能评价方法的引进、消化和再创新及应用.

The test methods for determining the connection performance of dowel type fasteners in wood structures in Europe and America are introduced,mainly including withdrawal test,lateral load test,pull-through resistance and dowel-bearing strength of dowel type fasteners,with the aim to promote relevant research related to wood structures in China.

The construction technology of nailed joint in timberwork used larch in the northeast of China have been studied. The result showed that when nailed joint used Larix gmelini, pre - drilled diameter was around 85 percent of the nail diameter and pre - drilled depth should exceed the into deep of nails. The nail was not too thick at the end of the nailed joint, test determined or adopt corresponding technical measures had to ensure that the connection performance.

The common production technology,the main points and the key technology were discussed.Several solutions were explored for resolving the problems that usually happen during production.This paper provided technical support for the production and quality of three-layer parquet.

单板层积材（Laminated Veneer Lumber，LVL）作为结构复合木材产品之一，与单板条层积材（Parallel Strand Lumber，PSL）、木条定向层积材（Laminated Strand Lumber，LSL）和定向刨花方材（Oriented Strand Lumber，OSL）等产品已经成为北美重要的木质工程材料，广泛应用于民用和商业木结构建筑。