Studies on the Extension, Compression and Shear of Rice Seedling Mats

Interrelationships between Extension, Compression and Shearing Characteristics

Abstract

The interrelationships between extension, compression and shearing characteristics of rice seedling mats were investigated, and it became clear that those had mutual relations each other. Therefore, mechanical properties of mats may be qualitatively grasped by knowing one of the factors for example, extension strength. This seems to give some sugges tions about measurement of the mechanical properties of mats and application of results.
All data of extension strength as a representative value were reexamined and mechanical properties were arranged. The extension strength obtained in this study ranged from 0.01 to 0.22kgf/cm² (0.98 to 21.56kPa). This in which range nearly overlapped to the one of actual rice seedling mats raising in the farms. It became clear that not only bed soil and the weight of root but also the strength of each root and root distribution remarkably affected the extension strength.
Furthermore, some qualitative considerations were given to the relationship between anisotropy and inner structure of mats i. e. condition of roots, to the representation of elastic, plastic and viscostic behaviours by a mechanical model, and to the failure criteria.
However, mechanical properties of mats was only understood comprehensively because of complication and difficulty.