Some parameters such as orientation, volume ratio, length and shape of fibers are so effective in improvement of final properties of composites. In previous study the influence of volume ratio and length of fiber on composite attributes was investgted. The effective shape and orientation of metal fiber in composite is the purpose of our reasherch.flat and waved steel fibers with 15 mm length were used in different orientation in composites structure to assess the effect of orientation and shape of fibers on composite modulus and strength. Also, two composites reinforced 30 mm endhooked and waved fiber were produced. To study the pull-out force and debonding force in pull-out test ,waved, endhook and flat fibers with different embedded length were applied.to study the effect of surface treatments on composites fracture , tow surface treatment in pull-out test and one surface treatment in strength test, were applied. The result show that changing fiber orientation in order to decrease the angle between fiber direction and in-plane direction will increase composite modulus and strength. In the other hand surface treatment will decrease the composite modulus , strength and toughness. The result obtain from Holpin-Tsai model is aggreable with this result experimental result in strength test. It is concluded that increasing the imbedded length will increase debonding force, debonding work and pull-out force. Also by changing the fiber from flat to wave kinds, pull-out work will enhanced .surface treatment will caused the increase in pull-out force.
