数字图像测量技术在小麦三轴试验中的应用研究

APPLICATION OF DIGITAL IMAGE PROCESSING TECHNIQUE ON TRIAXIAL TEST OF WHEAT

将基于数字图像测量技术的三轴试验仪应用于测试粮食剪切强度及变形特性。选取河南小麦为研究对象,进行了围压25、50、75、100 k Pa下的三轴试验,并采用数字图像测量技术对试样剪切变形全过程进行监控。研究结果表明,基于数字图像测量技术的三轴试验可方便测试粮食剪切强度和变形特性。试验获得的小麦内摩擦角为25.13°。由小麦体变-应变曲线及变形图分析了剪切变形发展过程,试样先减缩然后发生剪胀现象,剪切破坏为鼓状破坏形式。研究结果表明,基于数字图像测量技术的三轴试验仪,适用于小麦剪切试验测试,能满足试验精度的需求,试验结果合理。

The triaxial test instrument based on the digital image processing technique(DIPT) was applied on the determination of shear strength and deformation characteristics of wheat. A series of triaxial tests were conducted on wheat selected from Henan with cell pressure of 25 k Pa to 100 k Pa,and the shearing deformation was monitored during the whole test process. The results showed that the triaxial test based on digital image processing technology could be used to test the shear strength and deformation characteristics of wheat expediently. The internal frictional angle was 25.13 degree. The development process of shear deformation was analyzed by volumetric-strain curve and deformation field obtained by DIPT. It was demonstrated that the volume was decreased firstly and then dilatancy phenomenon occurred,until the drum shape deformation was presented. It was concluded that the triaxial tests with DIPT was suitable for the tests of strength and deformation characteristics of wheat. And the afforded results was reasonable,which could satisfied the precision of test result.