The Effect of Fiber Breakage on Transient Stress Distribution in a Single-Lap Joint Composite Material

Document Type: Research Paper


1 Department of Mechanical Engineering, Shahid Chamran University

2 Department of Mechanical Engineering, Bu-Ali Sina University


In the present study, the transient stress distribution caused by a break in the fibers of an adhesive bonding is investigated. Transient stress is a dynamic response of the system to any discontinuity in the fibers from detachment time till their equilibrium state (or steady state). To derive the governing dynamic equilibrium equations shear lag model is used. Here, it is assumed that the tensile load is supported only by the fibers. Employing dimensionless equations, initial conditions and proper boundary conditions, the differential-difference equations are solved using explicit finite difference method and the transient stress distribution is obtained in the presence of discontinuities. The present work aims to investigate the transient stress distribution in a single-lap joint, caused by the fiber breakage in a single layer of the adhesive joint. For this purpose, the effect of different number of broken fibers (including mid fiber) in the adherend on load distribution in other intact filaments, the location of fiber breaks in the adherend, and the effect of adhesive length is studied on the overall joint behavior. The results show that a the fiber is broken away, the amount of initial shock (maximum load) into the fiber and thus the dynamic overshoot is reduced. Maximum amount of shock in the lateral fibers is broken at this point due to breakage in the thirteenth fiber maximum axial load and shock are introduce to the fourteenth fiber.


[1] Mohseni Shakib M., 2011, Mechanics of Composite Structures, Imam-Hossein University, First Edition ,Tehran, Iran.
[2] Pickett A. K., Hollaway L., 1985, The Analysis of elastic adhesive stresses in bonded lap joints in FRP structures, Composite Structures 3: 55-79.
[3] Nedele M. R., Wisnom M. R., 1994, Stress concentration factors around a broken fiber in a unidirectional carbon fiber-reinforced epoxy, Institute of Structures and Deisgn 25: 549-557.
[4] Rajabi I., Rahimi F., Bakhshandeh K., 2007, Effects of single-Lap stress concentration in composite adhesive joints, The 14th International Conference on Mechanic(ISME), Isfahan, Iran.
[5] Wang Z. Y., Wang L., Deng H., Tong J. W., Aymerich F., 2009, An investigation on strain/stress distribution around the overlap end of laminated composite single-lap joints, Composite Structures 89: 589-595.
[6] Beylergil B., Cunedioglu Y., Aktas A., 2011, Experimental and numerical analysis of single lap composite joints with inter-adherend fibers, Composite Part B 42: 1885-1896.
[7] Challita G., Othman R., 2012, Analytical model of the double-lap bonded joints response to harmonic loads, European Journal of Mechanics A/Solids 34: 149-158.
[8] Mokhtari M., Madani K., Belhouari M., Touzain S., Feaugas X., Ratwani M., 2013, Effect of composite adherend properties on stresses in double lap bonded joints, Materials and Design 44: 633-639.
[9] Mousavitabar H., 2010, Stress Analysis of Composite Adhesive Joints, M.Sc Thesis, Department of Mechanical Engineering, Shahid Chamran University, Ahwaz, Iran.
[10] Daniali M., 2012, Investigation of Stress Concentration Due to Crack Existence in Composite Joint, M.Sc Thesis, Department of Mechanical Engineering, Shahid Chamran University, Ahwaz, Iran.
[11] Hedgepeth J. M., 1961, Stress Concentration in a Filamentary Structures, Technical Note, D-882.
[12] Mirshekari E, 2010, Transient Response of Stress Distributions in a Laminate Subjected to the Crack, M.Sc Thesis, Department of Mechanical Engineering, Shahid Chamran University, Ahwaz, Iran.
[13] Chapra S.C., Canale R.P., 2010, Numerical Method of Engineering, McGraw-Hill, New York .
[14] Logan D.L., 2007, A First Course in the Finite Element Method, Thomson, University of Wisconsin-Platteville.