Bearing stiffness of glass fibre-reinforced polyester: influence of coupon geometry and laminate properties

The bearing stress–strain response of glass fibre-reinforced polyester (GRP) laminates in a single-bolt double lap joint was investigated experimentally and numerically. Six GRP laminate types were tested according to the ASTM D5961 procedures for three coupon geometries. A 2-D finite element model that included material non-linearity, clearance and bolt–hole friction predicted the bearing stiffness very accurately. However, both numerical and experimental data disagreed with existing joint flexibility models developed for metals or carbon fibre-reinforced epoxy laminates with tight fitting bolts. Clearly, some adaptation of the joint flexibility formulae is needed when they are used for design of GRP structures with large bolt–hole clearance. On average, joints with a reduced width (w/D=2) were 26% more compliant than three times wider standard joints (w/D=6). Doubling the end distance had a smaller effect on the bearing stiffness. Laminates with more axial reinforcement had a clearly higher bearing stiffness for the small coupon width (w/D=2). For wider coupons (w/D=6), this trend became less apparent.

[1]  William Barrois,et al.  Stresses and displacements due to load transfer by fasteners in structural assemblies , 1978 .

[2]  N. Pagano,et al.  The Laminate Approximation for Randomly Oriented Fibrous Composites , 1969 .

[3]  Bart Vangrimde,et al.  Analysis of the bearing response test for polymer matrix composite laminates: bearing stiffness measurement and simulation , 2002 .

[4]  Fabrice Pierron,et al.  A Numerical and Experimental Study of Woven Composite Pin-Joints , 2000 .

[5]  M. W. Hyer,et al.  Analysis of multifastener composite joints , 1994 .

[6]  Geoffrey Turvey.  Single-bolt tension joint tests on pultruded GRP plate — effects of tension direction relative to pultrusion direction , 1998 .

[7]  N. Ohmae,et al.  Chapter 7 - Friction and Wear Performance of Unidirectionally Oriented Glass, Carbon, Aramid and Stainless Steel Fiber-Reinforced Plastics , 1986 .

[8]  S. Tsai,et al.  Introduction to composite materials , 1980 .

[9]  Edwin Baumann.  Finite element analysis of advanced composite structures containing mechanically fastened joints , 1982 .

[10]  C. Cooper,et al.  Effects of joint geometry and bolt torque on the structural performance of single bolt tension joints in pultruded GRP sheet material , 1995 .

[11]  P. K. Mallick,et al.  Composites engineering handbook , 1997 .

[12]  T. A. Collings,et al.  Bearing deflection behaviour of a loaded hole in CFRP , 1984 .

[13]  D. Denton.  Mechanical Properties Characterization of an SMC-R50 Composite , 1979 .

[14]  J. Clarke.  Structural design of polymer composites : EUROCOMP design code and handbook , 1996 .

[15]  Victor Giurgiutiu,et al.  Development of Strength Theories for Random Fiber Composites , 1994 .

[16]  T. Yue,et al.  Stress analysis of finite composite laminate with multiple loaded holes , 1999 .

[17]  Bruce L. Bunin,et al.  Critical joints in large composite aircraft structure , 1983 .

[18]  Liyong Tong,et al.  Bearing failure of composite bolted joints with non-uniform bolt-to-washer clearance , 2000 .

[19]  H. Huth,et al.  Influence of Fastener Flexibility on the Prediction of Load Transfer and Fatigue Life for Multiple-Row Joints , 1986 .

[20]  John M. Potter,et al.  Fatigue in mechanically fastened composite and metallic joints : a symposium , 1986 .

[21]  R. Boukhili,et al.  Descriptive relationships between bearing response and macroscopic damage in GRP bolted joints , 2003 .

[22]  Pedro P. Camanho,et al.  Stress analysis and strength prediction of mechanically fastened joints in FRP: A review , 1997 .

[23]  L. Hollaway,et al.  The experimental behaviour of bolted joints in pultruded glass/ polyester material. Part 2: Two-bolt joints , 1993 .

[24]  Ramamurthy Prabhakaran,et al.  AN EXPERIMENTAL INVESTIGATION OF LOAD-SHARING IN A MULTI-BOLT PULTRUDED COMPOSITE JOINT , 1998 .

[25]  Sergey V Shkarayev,et al.  Analysis of composite laminates with multiple fasteners , 1998 .