马铃薯的累积损伤特性

马铃薯在采收、加工和运输过程中易受挤压、碰撞等作用而产生损伤。本文切取鲜食马铃薯试样，使用质构仪进行压缩试验模拟挤压和碰撞损伤，通过一个试样的多次压缩模拟累积损伤。论文通过分析马铃薯试样在不被破坏的前提下受一次、多次压缩后的位移-负载关系，研究经过多次不同负载压缩后马铃薯的塑性形变规律，分析其在不同作用力多次作用下的累积损伤特性。结果表明：经多次累积作用，不会改变马铃薯的临界破坏点。马铃薯存在生物屈服点，当受力超过生物屈服点后可能不会破坏，但马铃薯会产生塑性形变，即损伤。得到了若经过多次压缩，马铃薯的损伤体积会累积增加，且当下一次压缩位移超出马铃薯试样压缩过的最大位移时，马铃薯的累积损伤体积增加较大；当下一次压缩位移小于马铃薯试样压缩过的最大位移时，累积损伤体积增加较小等损伤累积规律。研究结果对于马铃薯采收、加工、转运装备的减损设计有指导作用。

Accumulative Damage Characteristics of Potato

Potatoes are easily damaged by extrusion and collision during harvesting, processing and transportation. In this paper, fresh potato samples are cut as a specimen, a Food Texture Analyzer is used to conduct compression tests to simulate extrusion and collision damages, and multiple compression of one sample is used to simulate accumulative damages. The displacement-load relationship of potato specimen is analyzed after being compressed for one or multiple times without being damaged. The plastic deformation characteristics of potato after multiple compression with different loads is studied, and its accumulative damage characteristics are analyzed. The results show that the critical failure point of potatoes will not change even under repeated loads, and there is a bio-yield point of potatoes when the force exceeds the bio-yield point, as well as potato plastic deformation which known as damages. The characteristics of potato accumulative damage show that the damage volume of potato will accumulate with multiple compression. Furthermore, the accumulative damage volume increases greatly when the next compression displacement exceeds the maximum displacement of the potato specimen compressed over, and the accumulative damage volume increases less when the next compression displacement is lower than the maximum displacement of the potato samples compressed over. The above results play a important role in the designing of potato harvesting, processing and transportation equipment.