INVESTIGAATION OF COMMPRESSIIVE PROOPERTIEES OF3D WOVEN FIBER REINFORCED POLYMERIC COMPOSITES THROUGH COMBINED END

Abstract

The compressive strength, internal failure mechanisms, and comparison of failure stress state of 2D fiber reinforced woven composites and 3D fiber reinforced angle-interlocked woven composite is investigated through experimental work, SEM, finite element analysis and failure theories. The aim for this research work is to check the feasibility of ASTM D6641 (which compression through combine end and shear loading method) for 3D fiber reinforced woven composites. A 3D finite element model is developed in ABAQUS based on homogeneous orthotropic laminate to investigate the stress variation and failure stress state in the gage section of the specimen. Two different failure theories in three dimensions are considered i.e. fully interactive three dimensional Tasi Wu failure criteria and limit criteria i.e. Maximum stress used for failure prediction. The broader aim of this research work is the development of testing standard for mechanical testing of 3D fiber reinforced woven composites. Through experimental work and finite element analysis it is found that compressive properties of 3D fiber reinforced woven composite is lower than the 2D fiber reinforced composite materials. SEM investigation is carried out to study the internal failure mechanisms in specimens. In 2D fiber reinforced composites the major cause of failure is fiber micro-buckling, fiber breaking and kink band formation, where as in 3D fiber reinforced composites the major cause of failure is fiber breaking and kinking at various locations. Finite element analysis shows that major compressive stresses are developed in the gage section and stress distribution is uniform. ASTM D6641 is used for compression testing of 2D fiber reinforced woven composites, when ASTM D6641 is used for compression testing of 3D fiber reinforced woven composites results shows higher standard deviation and coefficient of variance. Based on Experimental work and SEM investigation we can use ASTM D6641 for testing 3D fiber reinforced woven composites.