Research On The Torsional Properties Of Filament Winding Tubes

In recent years, as the country's strong support for low-carbon economy, owing to the outstanding performance of resin-based composite materials in several respects such as corrosion resistance, light weight, high strength and designable made their research and applications become more and more important. At present, composites is used as structure materials to substitute metal material, with high specific strength, excellent thermal insulation composites is paid more and more attention in transportataion.Therefore,annlysis of torsional performance is vital for composite materials.In this paper, using moderate temperature curing epoxy resin, tubes were made with different ply and thickness by wet filament winding process. The effects of various factors such as winding angles and thickness on the torsional properties were also studied by testing resin content and buckling torque. Analysis of the breaking specimen by commercial finite element software with maximum stress criterion and Tsai-Wu criterion. Finding failure index at two failure criterion and calculate the buckling torque of samples according to the index result,then compared with the actual buckling torque to look for a method which could predict the buckling torque of winding tubes.The result shows that with the winding angle of the sample increases, the buckling torque and maximum shear stress decreases, while the thickness of the specimen also decrease with the increase of the angle.when it was 3 layers, the buckling torque and maximum shear stress of 25°specimen was increased 132% and 45% than the 60°. When the winding angles fixed at 25°,the buckling torque and maximum shear stress of 3 layers was increased 58% and 128% than 2 layers,respectively.The more layers, the better torsional properties. The properties of specimen with winding angles 25°/60°/25°and 60°/25°/60°was close to the specimen of 25°so we can enhance the properties of other direction by selecting appropriate fiexed angles and do not cut down the torsional properties at the same time.In addition,all tubes showed compression failure at the direction along the wingding angle and accompanied with delamination.It can be more accurately predicted the buckling torque of 45°and 55°specimen by Tsai - Wu criterion,but can't predict the buckling torque of 25°by defined failure index. In roder to make it more accurate,we compared with actual buckling torque to correct failure index. For the mixed layer specimens, the failure mode is more complex, it need to consider the buckling of different ply, the actual valu of buckling torque between the minimum torque layer and the maximum torque layer.