Exploring Strain Characteristics and Bearing Capacity of a Carbon Filament-Wound Composite Cylindrical Shell under Hydrostatic Pressure

静水压力下碳纤维缠绕复合材料圆柱壳体应变特性及承载能力研究

¹ Structural Ceramics and Composites Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
² School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
³ Key Laboratory for Unmanned Underwater Vehicle, Northwestern Polytechnical University, Xi'an 710072, China

Received: 3 September 2019

Abstract

In order to study the strain characteristics and bearing capacity of a filament-wound composite cylindrical shell and its different dome structures under hydrostatic pressure, experiments were carried out. Firstly, static tests were conducted to study the axial and circumferential strain of the composite cylindrical shell on its different positions. The bearing capacity of the ellipsoid dome was compared with that of the hemisphere dome. The blasting test and the nonlinear analysis of the strain were conducted. The relationship between the strain trend and the crack propagation path was studied, and the structural failure mode was explored. The study shows that as the hydrostatic pressure increases, the strain increases and that the strain amplitudes of measuring points gradually appear different and show varying degrees of nonlinearity. Along the circumferential direction of the circumferential crack, the axial strain amplitude gradually decreases by 20%. But the circumferential strain amplitude gradually increases by 94%. As the load of the composite cylindrical shell increases to a certain extent, its final failure mode is strength failure, but its instability is not obvious.

摘要

为研究静水压力下纤维复合材料圆柱壳体及不同封头结构形式的应变特性及承载能力，首先开展了静力测试研究。测试了舱体内不同测点的轴向应变和环向应变，并且对比分析了椭球封头和半球封头承载能力。进行爆破实验测试，开展应变非线性分析，研究测点应变与裂纹扩展路径的关联，探究结构破坏模式。结果表明：随着载荷的增加，应变增加，不同测点的应变幅值逐渐表现差别，呈不同程度的非线性；沿圆周裂纹的顺时针方向，轴向应变幅值逐渐降低，降幅达20%，环向应变幅值逐渐增加，增幅达94%；载荷增加到一定程度，舱体最终的失效模式是强度破坏，失稳形态不明显。