the aim of this research is to study the effect of changing the geometric shape of fibers which are used to reinforce the composite materials, The composite material consists of polyester as a matrix(87% w.t) and fibers(13% w.t) as a reinforced that have different cross-section area shapes used (circular, triangle, and square). A bending test was performed on composite materials and matrix material, the results showed that the composite material reinforced with steel fibers with a circular shape has a bending strength higher than composite materials reinforced with steel fiber that has a triangle and square shape in a cross-section area, the results also showed that the lowest bending strength was for the matrix material.
Key word : composite materials, fibers, polyester, bending test.
The mechanical and physical properties of materials may change if they are exposed to external stresses, there for modern technologies require materials with unique properties, therefore, there was a need to discover new materials that bear new qualities and properties that are not available in ordinary alloys or ceramic materials, especially materials that are used in outer space applications