Structural strength analysis and optimization of portable hydrogen storage vessel made of fiberglass tube

Compared to steel, glass has higher strength and lower density, which makes it stand out as a pressure resistant vessel for hydrogen storage. However, glass easily breaks when it encounters locally concentrated stress. For high pressure hydrogen storage, the stress distribution of a glass vessel during pressure loading needs to be homogeneous without local stress concentration. Herein, the stress-strain behavior of portable hydrogen storage vessels made of glass fiber tubes is investigated theoretically and experimentally, respectively. The effects of different glass materials, wall thickness and pressure on the strength of the microtubes are investigated. Meanwhile, the method of filling the triangular gaps and adding solid fiberglass border was proposed to reduce the stress concentration. The result reveals that glass materials have little effect on the strength of microtubes. The optimal wall thickness is 12.5 μm for microtubes with an inner diameter of 100 μm. Filling the triangular gaps can reduce stress and expansion. The arrayed microtubes with solid fiberglass border are less deformed during fiber drawing technique. The stress increases at the tangent point of the arrayed microtubes with solid fiberglass border, but the stress of the outermost microtubes is significantly decreases.