Experimental Study On Reinforcement Design For Composite Lanate With A Large Cutout

As composite materials has been used in Aviation and Space structures moreand more widely, Structural designers must place some cutouts in the compositestructures because of the functional requirements, such as pipeline arrangement,equipment maintenance, etc. and the cutouts maybe would weaken the loadcarryingcapacity of the laminate structure, Large cutout is the most difficult toreinforce due to its stronger influence district of discontinuity which is caused bythe cutting of fibers So the research on reinforcement of composite laminate with alarge cutout is necessary.In this paper,first of all,the different decline degree of mechanicalperformance is compared and analyzed when cutouts with different shape are cut inthe composite laminate. An elliptical cutout which maintenance staffs could passthrough conveniently is designed, and with finite element software tools theinfluence of the elliptical cutout on stress/strain concentration factor and criticalbuckling load of the structure is investigate. Next, two reinforcement measures arelayout, Symmetric submerged reinforcement and mental piece reinforcement.Finally, experiment on the models which have been designed sustain shear load areconducted. By this test, the influence law of the large openings for the mechanicalbehavior of laminates could been explored. The reinforcement effectiveness andreinforcement efficiency of two determined reinforcement measures are evaluatedby comparing the simulation results and experiment results, also the effectivenessof cutout reinforcement design program.Prior to the experiment in this paper, there was nobody have completed suchexperiment like which is in this paper in china. Results of this study show that theinfluence to stress/strain distribution and buckling property as a result of largecutout opening is greater than conventional cutout and composite submergedreinforcement is more efficient than the measure of mental piece reinforcement.