What is the limitations of composite materials?

Question

like glass-fibre reinforced plastic how long their life span?

and due to any pressure or anything? will glassfibre break or it will last?

Answer 1

Well, the glass fibre portion of the composite is the most stable part of the mix.  It will last for many decades without problems.

The tougher part is the plastic used to mold and bind the layers of glass fibres together.  Typically, the resins used are either a polyester or a vinyl ester based material.  These are prone to degradation due to the environment.  This too can be controlled, based on what kind of modifiers are added to the resin, and what kind of elements they are exposed to.

As you can see, life span of these composites is subject to many variables, and is variable, itself.  Realisitcally, if you are careful to tailor the material to the environment that it will be used in, you should expect about 20 years of reliable service.