Seemann Composites Resin Infusion Molding Process (called SCRIMPTM for short) is a resin transfer molding process which is commonly used in the manufacture of yachts. Fiber-Reinforced Plastic (called FRP for short) manufactured by using SCRIMP has higher fiber-volume-content than that manufactured by using Hand Lay-Up Process (called HLUP for short). In general, the tensile strength and fatigue strength are used to compare the tensile properties of SCRIMP-FRP and HLUP-FRP. In this paper, another viewpoint of comparison is used to compare their tensile properties, especially their fatigue tensile properties. Experiments on the fatigue life and damage phenomena in SCRIMP-FRP and HLUP-FRP were performed. Experimental results show that if the same fibers are used in SCRIMP-FRP and HLUPFRP, SCRIMP-FRP will be much thinner than HLUP-FRP and few air bubbles exist inside SCRIMP-FRP. Although SCRIMP-FRP has higher tensile strength than HLU-FRP, the tensile forces they can bear are approached. That means, processes do not affect the tensile load carrying capacities of FRP. However, SCRIMP-FRP exhibits shorter fatigue life than HLUP-FRP. The reason for that is discussed in this paper and qualitative analysis is performed to explain the author's contentions.

This work explores the sound transmission loss provided by the orthotropic multi-layers to elucidate the sound insulation of FRP (Fiber Reinforced Plastics). Mat is the major material considered in the numerical works. The transfer matrices of a single layer of the orthotropic laminate and the fluid are determined. Further, the boundary conditions on the various interface planes are arranged into matrix form. Combining the transfer matrixes and the boundary conditions and applying the transfer matrix method (TMM) yields the surface impedance and the sound transmission loss. The sound-propagation characteristics are studied. Additionally, the STC (Sound Transmission Class) of FRP and steel are compared and discussed.