What factors affect the performance of composite pressure vessels?

The performance of composite pressure vessels is affected by a variety of factors, including material properties, manufacturing process, design factors and the use of environmental aspects, as follows:

Material properties

Fiber properties: the strength, modulus, elongation at break and other mechanical properties of the fiber directly affect the pressure vessel's carrying capacity. For example, carbon fiber has a high specific strength and high specific modulus, which enables the pressure vessel to withstand high pressure while maintaining a light weight. In addition, the corrosion resistance and temperature resistance of the fiber will also affect the performance of the vessel in different working environments.

Resin Properties: Resin, as the matrix material, serves to bond the fibers together and transfer the load. The strength, toughness, heat resistance, chemical resistance and other properties of the resin have an important impact on the overall performance of the pressure vessel. For example, epoxy resin has good bonding properties and high strength, but the toughness is relatively poor; while polyurethane resin has good toughness and low temperature resistance.

Fiber - resin interfacial bonding properties: the interfacial bonding strength between the fiber and the resin determines the load transfer efficiency between the fiber and the resin. Good interfacial bonding can make the fiber give full play to its load-bearing capacity, improve the strength and fatigue resistance of the pressure vessel. If the interfacial bonding is poor, the fiber and resin will be easily debonded when the force is applied, leading to premature failure of the vessel.

Manufacturing process

Fiber layup: the angle, order and number of layers of fiber layup will affect the strength and stiffness distribution of the pressure vessel. Reasonable layup design can make the vessel have suitable mechanical properties in different directions to withstand complex internal pressure and external loads. For example, using a combination of spiral and annular winding can improve the axial and annular strength of the pressure vessel.

Molding process: Different molding processes can lead to differences in the internal structure and properties of composites. For example, fiber winding molding process can accurately control the distribution and tension of fibers, and produce pressure vessels with high fiber content and uniform strength; while hand-paste molding process is flexible, but the product quality is greatly affected by human factors, and is prone to problems such as uneven distribution of fibers and inconsistent resin content.

Curing process: Curing temperature, curing time and curing pressure and other curing process parameters have an important impact on the performance of composites. Appropriate curing process can make the resin fully cross-linking reaction, improve the performance of resin and fiber - resin interface bond strength. Incomplete curing will result in insufficient resin strength and reduced mechanical properties of the container.