棕榈藤材的抗弯强度测试方法

棕榈藤藤材具有独特的弯曲特性,目前国内外缺乏相应测试标准。利用我国两种主要的商用棕榈藤材,分别对其带皮圆形整藤和不含藤皮的矩形藤片试材进行了中央单点加荷的三点弯曲试验,考察了不同加载速率、不同试材尺寸和不同跨高比的影响。结果表明,单叶省藤材和黄藤材的适宜加载速率分别为20 mm/min和10 mm/min;在跨距一定的情况下,本实验中的几种弯曲测试基本都符合要求;对于跨高比为12的弦向藤片加载,其数据变异最小;对于整藤试材的三点弯曲测试,其跨距应为藤材直径的6倍以上,考虑到藤材弯曲挠度较大,建议跨距为6~8倍藤径。

Testing on the method of bending strength of rattan cane

Rattan canes are of particular flexural properties,lacking the standard testing methods of rattan canes at home and abroad.The Calamus simplicifolius cane and Daemonorops margarita cane are the main commercial rattan canes in China.Through the round whole canes including the bark and the rectangle cane pieces without the bark of the two rattans,the middle loading three-point bend test was done on the different loading rates,specimen dimensions and span-to-depth ratios were discussed.The results showed that: the loading rate for C.simplicifolius cane and D.margarita cane should be different,they are 20 mm/min and the 10 mm/min respectively;with the same span,all the measure methods in this study could meet the bend testing requirements.Under the conditions of the span-to-depth ratio of 12 the bending strength and the bending elastic modulus of the canes had the minimum variation.For the round whole rattan canes with the outer bark,the span should exceed the 6 times cane diameter.Considering the large bending deflection of rattan cane,the span-to-depth ratio of 6-8 was proposed for its three-point bending.