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

Kechun Shen,Yao Shi,Zhun Li,Guang Pan,Ranfeng Wei

doi:10.1051/jnwpu/20203850937

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.

Highlights

Finite Element Analysis of the Failure Mode of Composite Sandwich Cylinders Subjected to Hydrostatic Pressure[ J]
The circumferential strain amplitude gradually increases by 94%
[8] 沈克纯, 潘光, 姜军, 等. 静水压力下纤维缠绕圆柱壳体的稳定性分析[ J] . 西北工业大学学报, 2018, 36(5) : 40⁃48 SHEN Kechun, PAN Guang, JIANG Jun, et al Stability of Filament⁃Wound Composite Cylinders Subjected to Hydrostatic Pres⁃ sure[ J]

Summary

Introduction

( ± θ2) 5 / ( ± θ3)5( ± θ4) 5] ,文献[8⁃9] 中设计平台优化结果为[ ( ± 90) 5 / ( ± 80) 5 / ( ± 40) 5( ± 90) 5] , 碳纤维复合材料为 T700S / 环氧, 由于生产工艺控制,纤维单层平均厚度为 0.154 mm, 为保证壳体壁厚为 8 mm,实际方案[ ( ± 90) 5 / ( ± 80) 5 / ( ± 40) 5 / ( ± 90) 5 / ( ± 80) 5 / ( ± 90) ] 。成型后的舱体如图 1 所示。实验工况包括静力测试和爆破测试,表 1 给出不同工况下每个阶段的保压值和保压时间。舱体应变测点位置标记如图 4 所示。 1.2 实验方案测试设备( 见图 3) 包括 30 MPa 高压釜和动态应变。从图中可以看出,当压力达到 7.1 MPa 时,相同方向测点应变值的差别达到最大,环向为 17.6%, 轴向为 5.51%。图 7 和图 8 给出 180°方位角处测点的应变情况,外压为 7. 1 MPa 时,环向最大差别为 2.93%、轴向为 5.82%。从图可以看出,高压釜卸载后测点应变并不为零,维持在微小水平,主要有几点原因:1卸载后高压釜压力等于当地供水压力为 0.45 MPa,故壳体仍产生应变;2应变片是由粘接剂粘贴在舱体壁面上,卸载后界面存在残余应变。

Results

Conclusion