ABSTRACT The plastic film materials are a widely used agricultural means of production. Recently, two types of new agricultural film mulches are developed and are used popularly. They are ethylene-vinyl acetate copolymer (EVA) and polyolefin (PO) film mulches. The transmittances of film mulches are related to thermal reservation and plant photosynthesis. We experimentally measure transmittances of several EVA and PO film mulches under different wavelengths. We also find that the transmittances of mulches vary with light intensity change at one wavelength. The variable transmittances for these mulches are also measured in experiments. These data measured can provides help for agricultural production and accurate numerical simulation for the establishment microclimate of plastic greenhouse, even the degradation of plastic films. Recently popularly ethylenevinyl ethylene vinyl (EVA (PO photosynthesis wavelengths wavelength experiments greenhouse films

Abstract Bird-strike failure of fan blades is one of the basic challenges for the safety of aircraft engines. Simplified slender blade-like plates are always used to evaluate the impact-induced damage mechanism at design stage. One undesirable issue is the failure at the root of clamped slender plates, which cannot recover the real case of twisted blades. For this purpose, three different strategies were exploited to obtain desirable deformation and stress responses, namely the impact location, additional weight, and the boundary condition. Numerical models of the simplified slender blade and the bird projectile were constructed by using finite element method (FEM) and smoothed particle hydrodynamics (SPH) approaches. The impact deformations and stress distributions were comparatively investigated in detail. The numerical results show that changing the boundary condition is the most effective way to obtain preferable impact responses for further failure analysis of real fan blades. Present results will be useful to future experimental design of simplified bird-strike testing.