棉秆压缩与剪切力学性能的研究

Study on Mechanical Property of Compression and Shearing of Cotton Stalks

棉秆的力学性能是棉秆收获、粉碎和压缩成型等机械设计中的重要参数。为此,采用电子万能试验机对棉秆茎干进行了顺纹压缩、横纹压缩和横纹剪切试验。通过试验得到棉秆茎干应力-应变的有关规律和强度极限。棉秆茎干顺纹压缩在弹性阶段应力应变呈线性关系,平均强度极限为21.26MPa,弹性模量为2082.65MPa;横纹压缩的强度极限仅为顺纹压缩的12.70%,两者的比例与木材接近;横压弹性模量为124.0MPa;棉秆横纹剪切的强度极限约为顺纹压缩的76.55%。

Mechanical property of cotton stalk is an important parameter for design machinery of harvesting,shattering and compressing the cotton stalks. In the paper adopting an electronic universal testing machine carry out experimental studies of along the grain compression,cross the grain compression,cross the grain shear of cotton stalk culm. Through the experimental studies can get stress-strain curves and yield limit of cotton stalk culm. In elastic phase the stress-strain curve presents linear relation in along the grain compression of cotton stalk culm,the average yield limit is 21. 26MPa,and the average Young＇s modulus is 2082. 65MPa. And the yield limit of cross the grain compression of cotton stalk culm is only 12. 70% of that of along the grain compression,the ratio is near to that of timber,and the average Young＇s modulus of cross the grain compression is 124. 0MPa. And the yield limit of cross the grain shear of cotton stalk culm is 76. 55% of that of along the grain compression.