# 적층각도를 지닌 CFRP 시험편에서의 크랙전파 특성

• Hwang, Gue Wan (Dept. of Mechanical Engineering, Graduate School, Kongju Univ.) ;
• Cho, Jae Ung (Division of Mechanical & Automotive Engineering, Kongju Univ.) ;
• Cho, Chong Du (Division of Mechanical Engineering, Inha Univ.)
• 황규완 (공주대학교 대학원 기계공학과) ;
• 조재웅 (공주대학교 기계자동차공학부) ;
• 조종두 (인하대학교 기계공학과)
• Accepted : 2016.10.10
• Published : 2016.12.01
• 29 38

#### Abstract

CFRP is the composite material manufactured by the hybrid resin on the basis of carbon fiber. As this material has the high specific strength and the light weight, it has been widely used at various fields. Particularly, the unidirectional carbon fiber can be applied with the layer angle. CFRP made with layer angle has the strength higher than with no layer angle. In this paper, the property of crack growth due to each layer angle was investigated on the crack propagation and fracture behavior of the CFRP compact tension specimen due to the change of layer angle. The value of maximum stress is shown to be decreased and the crack propagation is slowed down as the layer angle is increased. But the limit according to the layer angle is shown as the stress is increased again from the base point of the layer angle of $60^{\circ}$. This study result is thought to be utilized with the data which verify the probability of fatigue fracture when the defect inside the structure at using CFRP of mechanical structure happens.

#### Keywords

Compact Tension Specimen;Layer Angle;Total Deformation;Strain Energy;Equivalent Stress;Carbon Fiber Reinforced Plastic(C.F.R.P)

#### Acknowledgement

Supported by : 한국연구재단

#### References

1. Song, K. N., Hong, S. D. and Park, H. Y., 2012, "Macroscopic High-Temperature Structural Analysis of PHE Prototypes Considering Weld Material Properties," Trans. Korean Soc. Mech. Eng. A, Vol. 36, No. 9, pp. 1095-1101. https://doi.org/10.3795/KSME-A.2012.36.9.1095
2. Kang, S. S. and Lee, J. H., 2011, "Evaluation of Fatigue Life and Structural Analysis for Dish-Type and Spoke-Type Automobile Wheels," Trans. Korean Soc. Mech. Eng. A, Vol. 35, No. 10, pp. 1315-1321. https://doi.org/10.3795/KSME-A.2011.35.10.1315
3. Song, K. N., Lee, H. Y., Hong, S. D. and Park, H. Y., 2011, "Macroscopic High-Temperature Structural Analysis Model of Small-Scale PCHE Prototype (II)," Trans. Korean Soc. Mech. Eng. A, Vol. 35, No. 9, pp. 1137-1143. https://doi.org/10.3795/KSME-A.2011.35.9.1137
4. Won, B. R., Jung, H. Y. and Han, J. S., 2013, "Structural Analysis and Shape Optimization for Rotor of Turbomolecular Pump Using P-Method," Trans. Korean Soc. Mech. Eng. A, Vol. 37, No. 10, pp. 1279-1289. https://doi.org/10.3795/KSME-A.2013.37.10.1279
5. Lee, D. H., Kim, H. S., Kim, B. K. and Lee, S. H., 2012, "Underwater Structure-Borne Noise Analysis Using Finite Element/Boundary Element Coupled Approach," Trans. Korean Soc. Mech. Eng. A, Vol. 36, No. 7, pp. 789-796. https://doi.org/10.3795/KSME-A.2012.36.7.789
6. Yoo, S. Y., Jun, B. H., Shim, H. W. and Lee, P. M., 2014, "Finite Element Analysis of CFRP Frame under Launch and Recovery Conditions for Subsea Walking Robot, Crabster," Trans. Korean Soc. Mech. Eng. A, Vol. 38, No. 4, pp. 419-425. https://doi.org/10.3795/KSME-A.2014.38.4.419
7. Park, C. W., 2011, "Injection Molding and Structure Analysis of Inline Skate Frames Using FEA," Trans. Korean Soc. Mech. Eng. A, Vol. 35, No. 11, pp. 1507-1514. https://doi.org/10.3795/KSME-A.2011.35.11.1507
8. Lee, J. O., Lee, Y. S., Lee, H. S., Jun, J. T., Kim, J. H. and Kim, C. G., 2008, "Structural Analysis on the Heavy Duty Diesel Engine and Optimization for Bearing Cap," Trans. Korean Soc. Mech. Eng. A, Vol. 32, No. 5, pp. 402-410. https://doi.org/10.3795/KSME-A.2008.32.5.402
9. Han, C. W., Oh, C. M. and Hong, W. S., 2013, "Stress Analysis for Bendable Electronic Module Under Thermal-Hygroscopic Complex Loads," Trans. Korean Soc. Mech. Eng. A, Vol. 37, No. 5, pp. 619-624. https://doi.org/10.3795/KSME-A.2013.37.5.619
10. Bao, C., Cai, L., Shi, K. and Yao, Y., 2015, "Estimation of J-resistance Curves for CT Specimen Based on Unloading Compliance Method and CMOD Data," Journal of Testing and Evaluation, Vol. 43, No. 3, pp. 517-527.
11. Sun, P. J., Wang, G., Xuan, F., Tu, S. and Wang, Z., 2011, "Quantitative Characterization of Creep Constraint Induced by Crack Depths in Compact Tension Specimens," Engineering Fracture Mechanics, Vol. 78, No. 4, pp. 653-665. https://doi.org/10.1016/j.engfracmech.2010.11.017
12. Wang, G., Liu, X. L., Xuan, F. and Tu, S., 2010, "Effect of Constraint Induced by Crack Depth on Creep Crack-tip Stress Field in CT Specimens," International Journal of Solids and Structures, Vol. 47, No. 1, pp. 51-57. https://doi.org/10.1016/j.ijsolstr.2009.09.015
13. Han, M. S., Choi, H. K., Cho, J. U. and Cho, C. D., 2015 "Fracture Property of Double Cantilever Beam of Aluminum Foam Bonded with Spray Adhesive," Journal of Mechanical Science and Technology, Vol. 29, No. 1, pp 5-10. https://doi.org/10.1007/s12206-014-1201-4
14. Cho, J. U., Lee, S. K., Cho, C. F., Sanchez, S. R., Blackman, R. K. and Kinloch, A. J., 2007, "A Study on the Impact Behavior of Adhesively-bonded Composite Materials," Journal of Mechanical Science and Technology, Vol. 21, No. 10, pp. 1671-1676. https://doi.org/10.1007/BF03177392
15. Liu, C. H. and Chu, S. J., 2014, "Prediction of Shape Change of Semi-elliptical Surface Crack by Fatigue Crack Growth Circles Parameter," Journal of Mechanical Science and Technology , Vol. 28, No. 12, pp. 4921-4928. https://doi.org/10.1007/s12206-014-1111-5
16. Jung, S. H. and Lee, H. G., 2011, "Crack-tip Opening Angle-based Numerical Implementation for Fully Plastic Crack Growth Analyses," Journal of Mechanical Science and Technology , Vol. 25, No. 5, pp. 1201-1206. https://doi.org/10.1007/s12206-011-0225-2
17. Wen, J. S., Ju, W. E., Han, T. K., Choi, S. T. and Lee, K. S., 2012, "Finite Element Analysis of a Subsurface Penny-shaped Crack with Crack-face Contact and Friction under a Moving Compressive Load," Journal of Mechanical Science and Technology , Vol. 26, No. 9, pp. 2719-2726. https://doi.org/10.1007/s12206-012-0741-8
18. Jung, S. H. and Lee, H. G., 2011, "Crack-tip Field Characterization of Crack-tip Opening Angle-based Crack Growth - Plane Strain Single-edge Cracked Specimen Subject to Pure Extension," Journal of Mechanical Science and Technology , Vol. 25, No. 5, pp. 1207-1213. https://doi.org/10.1007/s12206-011-0226-1
19. Wu, Y. J., Wang, J. J. and Han, Q. K., 2012, "Contact Finite Element Method for Dynamic Meshing Characteristics Analysis of Continuous Engaged Gear Drives," Journal of Mechanical Science and Technology, Vol. 26, No. 6, pp. 1671-1685. https://doi.org/10.1007/s12206-012-0416-5
20. Cho, H. S., Cho J. U. and Cho, C. D., 2015, "Experimental and Analytical Verification of the Characteristics of Shear Fatigue Failure in the Adhesive Interface of Porous Foam Materials," Journal of Mechanical Science and Technology, Vol. 29, No. 6, pp. 2333-2339. https://doi.org/10.1007/s12206-015-0525-z
21. Bang, H. J., Lee, S. K., Cho, C. D. and Cho, J. U., 2015, "Study on Crack Propagation of Adhesively Bonded DCB for Aluminum Foam using Energy Release Rate," Journal of Mechanical Science and Technology, Vol. 29, No. 1, pp. 45-50. https://doi.org/10.1007/s12206-014-1207-y
22. Gao, T., Kinloch, A. J., Blackman, B. R. K., Sanchez, F. S. R., Lee, S. K., Cho, C. D., Bang, H. J., Cheon, S. S. and Cho, J. U., 2015, "A Study of the Impact Properties of Adhesively-bonded Aluminum Alloy Based on Impact Velocity," Journal of Mechanical Science and Technology, Vol. 29, No. 2, pp. 493-499. https://doi.org/10.1007/s12206-015-0109-y
23. Parida, S. K. and Pradhan, A. K., 2014, "3D Finite Element Analysis of Stress Distributions and Strain Energy Release Rates for Adhesive Bonded Flat Composite Lap Shear Joints Having Preexisting Delaminations," Journal of Mechanical Science and Technology, Vol. 28, No. 2, pp. 481-488. https://doi.org/10.1007/s12206-013-1116-5