Rolling contact fatigue investigation and experimental simulation for plastic film used for full-opening and partially-opening automatic ventilation greenhouses

Abstract

The green house is widely used to add the quality and value of agricultural products. Newly developed full opening type green house has a lot of attracted attention because the roof opens and closes automatically in order to control the inside temperature. However, since the roof opens and closes very often, the cover sheet can be used only for 3-4months. This is because the plastic film is damaged between the support and rolling pipes during opening-closing affected by fatigue and wear. In this study, by using Scanning Electronic Microscope (SEM) and roughness test machine, the damage mechanism is investigated for the several plastic films. Then, FEM analysis is performed to evaluate the mechanical damage of plastic film between the pipes under different conditions and film materials. Also rolling fatigue experiments are performed to investigate the damage under different film materials. Then the results are compared with the FEM analysis. It is found that the thickness reduction of the film obtained under static contact analysis is the most important factor to control the damage of the film.