FEM을 이용한 Hole가공 CFRP 적층판의 응력 해석

Abstract

Due to development of core techniques the IT electronics industry can condense into lightweight and slimmer components have gained increasing attention. Composites have emerged as a attention for reducing the weight of such components. Since Carbon Fiber Reinforced Plastic(CFRP) is lighter and superior in specific strength, specific stiffness, fatigue strength, and chemical resistance compared to metal materials, it has been widely used in various industry fields. In order to manufacture small products with CFRP, it would be best to make the device all-in-one but due to size and shape of components. but it is difficult to manufacture a single unit. Produced by partial CFRP should be used for fastening elements when combined with the structural characteristics dissimilar materials to screw and rivets. For that Should the Hole machining CFRP laminates. However, the hole-processed CFRP laminate brings on the intensity decline due to the carbon fiber fracture and matrix destruction compared to the general CFRP laminate. CFRP is different fracture to the other with the metal because various studies are underway to save the mechanical properties. but a situation there is no research on small Hole machining CFRP. The objective of this sudy is to obtain the material properties for machining the hone on CFRP and Clarify reductions in the strength of non-hole CFRP laminate with hole. Also using Non-Hole CFRP material properties for general purpose finite element analysis program, it interpreted the Hole machining CFRP. In addition to CFRP materials properties as stated in the previous study and interpretation of the purpose finite element analysis program on Hole machining CFRP, compared with this experimental, the general-purpose finite element analysis programs to verify the reliability. Experimental method have produced for hole process CFRP each specimen's stacking angle of [15°/-15°]10, [30°/-30°]10, [45°/-45°]10, [60°/-60°]10, [0°/90°]10, [90°/0°]10 and drilled a 1.44m wide hole in the middle of specimen. In case of tensile test, experiment has been carried out by applying equal amount of displacement of 2 mm/min with UTM. After acquiring the physical properties of the CFRP material Hole machining the stress-strain diagram as shown. In accordance with conclusions are as follows: As a result of tensile test by hole processing lamination angles, the intensity and hardness was measured lower in the stress-strain rate of [0°/90°]10, [90°/0°]10 lamination specimen than in the [±15°]10 lamination specimen. If the linear graphof [±15°]10 specimen becomes closer to the [±45°]10 specimen as the lamination angle becomes big in the hole processing tensile test, it turns into the nonlinear graph. It is considered as the shear slip phenomenon by the shear angle. The [±45°]10 specimen of the general-purpose finite element analysis program represented a linear pattern in the stress-strain diagram, it is judged to have occurred because the nonlinear elements in the finite element analysis program did not converge. If the load direction and displacement lead to laminate at an angle closer to 45° look to the actual experimental values in the non-linear FEM analysis is interpreted as a linear error range it showed significant strength in comparison. Strength Analysis of CFRP closer to 45° on stress analysis of laminated CFRP Laminates Using ANSYS Analysis Tool (ACP) These results are considered to require a separate analysis of nonlinear models.