Experimental Study On Mechanical Properties Of 2.5D Satin Weave Composites

In this paper,2.5D similar satin woven composites have been studied.The research includes the three aspects:In the first part,based on "zig-zag" warp path assumptions,2.5D similar satin woven composites and 2.5D plain woven composites were designed,according to the principle of equal fibre volume of warp and weft yams.The microstructural difference of 2.5D plain fabric is compared to provide support for the analysis of the influence of meso structure on the mechanical properties of the composite.The results show that the error between the designed value and the true value of the volumetric fiber content of the two fabrics was 1.93%and 0.3%,respectively,with good agreement.In the second part,the tensile,compressive and flexural properties two kinds of composites were tested.The results show that:(1)For the 2.5D similar satin woven composites,the compressive strength and modulus in the warp direction are higher 43.55%and 23.95%,respectively,than that in the weft direction;the bend strength and modulus in the warp direction are lower are 55.86%and 45%,respectively,than that in the weft direction.(2)Compared to with 2.5D plain woven composites:the tensile strength and tensile modulus of 2.5D similar satin composites in the warp direction are higher 12.95%and 36.18%,respectively;the tensile strength and tensile modulus of 2.5D similar satin composites in the weft direction are higher 31.32%and 53.32%,respectively;along the warp and weft of 2.5D similar satin woven composites are lower 55.33%and 53.84%,respectively.the compressive strength and the compressive modulus of 2.5D similar satin woven composites in the warp direction are higher 87.35%'and 38.12%,respectively;the' compressive strength and the compressive modulus of 2.5D similar satin woven composites in the weft direction are higher 73.17%and 58.29%;the flexural strength in the warp direction is higher 10.34%and the flexural modulus in the warp direction is lower 3.33%;The flexural strength and the flexural modulus in the weft direction are higher 110.76%and 25%,respectively.The comprehensive analysis shows that 2.5D similar satin woven composites have better tensile,compressive and flexural properties than 2.5D plain woven composites.In the third part,the strain of the whole filed was record by Digital Image Correlation method in the process of stress on the surface of composite samples.The strain distribution of the two types of composite samples was uniform and the local high strain appeared.By observing the failure failure morphology under the tensile,compressive and bending load conditions of the specimens,it can be preliminarily concluded that:(1)The yarn is separated from and has no fracture in the weft tensile of 2.5D similar satin woven composites.2.5D similar satin composite tensile fracture specimen in the warp direction more neat,with a better overall structure.(2)There is a similar angle between 2.5D simialr satin composite specimens compression failure fractrue and stress direction,and the overall fracture height,the performance of the better brittle fracture characteristics.(3)The interface strength of resin and yarn of 2.5D similar satin woven composites is better.The main bending failure samples are yarn breakage and degumming,and no obvious resin peeling phenomenon appears.