Joints finite-element analysis

FINITE ELEMENT ANALYSIS AND EVALUATION OF THE TENSILE LOAD BEARING CAPACITY OF THE CO-CURED LAP JOINTS... 

In this study, residual thermal stresses were also eonsidered because co-cured lap joints generally undergo temperature drop (from 120D to 20D) during the curing process. The stress distributions in the co-cured single and double lap joints were analyzed using ABAQUS i.8 to be commercial finite element analysis software [21],... 

As previously mentioned, the single lap joint is the most common test used to evaluate adhesives because of its practical resemblance to many real-world joint designs. The adhesive lap joint has proven useful over the years and will likely continue to be widely used in the future. This paper discusses some of the complexities of the lap joint. The discussion will now concentrate on using finite element analysis to aid in a fracture mechanics approach to aid in understanding the mechanics of a lap joint. It will, to some extent, explore the validity of the design rules discussed above and look at the affect of some of the joint features that are not considered in these rules. 

BP s involvement in the manufacture of composites began in 1979 with the acquisition of Rolls Royce s composites activities our research programmes were targeted on areas fundamental to support of the aerospace composites activity, such as polymer chemistry, finite element analysis, materials science and testing. The ability to direct this work towards real components identified by the business was crucial to the success of the blocker door programme this was due, in part, to the use of a joint technical/commercial marketing team. 

Oskouei RH, Keikbosravy M, Soutis C. Estimating clamping pressure distribution and stiffness in aircraft bolted joints by finite element analysis. J Aerosp Eng Part G Proc Inst Mech Eng JAER0596 2009 223 863-71. 

McCarthy MA, McCarthy CT, Lawlor VP, Stanley WF. Three-dimensional finite element analysis of single-bolt, single-lap composite bolted joints part I — model development and vahdation. Compos Struct 2005 71(2) 140—58. 

Gray PJ, McCarthy CT. A global bolted joint model for finite element analysis of load distributions in multi-bolt composite joints. Compos Part B-Engineering 2010 41(4) 317-25. 

McCarthy MA, McCarthy CT. Finite element analysis of the effects of clearance on single-shear, composite holted joints. Plastics, Ruhher Compos 2002 32(2) 65—70. 

S Roy and J N Reddy, A finite element analysis of adhesively bonded composite joints with moisture diffusion and delayed failure , Computers Structures 1988 29(6) 1011-1031. 

Barton, N., Hansteen, H. (1979). Very large span openings at shallow depth deformation magnitudes from jointed models and finite element analysis. In proceedings of the 4 rapid Excavation Tunneling conference, (Vol. 2) (pp. 1331-1353), Atlanla,GA. 

Scarf joint. The importance of testing adhesive fracture under mixed-mode stress conditions has been noted. In the scarf joint (Fig. 4.14(e)), the applied load is resolved in the bondline to Mode I and Mode II components and their ratio changes with the scarf angle, < >. Bascom et al. 26, 70) investigated the effects of bondline thickness and test temperature, and G,i. n)c for < ) = 45° was calculated from the failure load and crack length using a finite-element analysis. A complex behaviour pattern emerged, as discussed... 

A number of cruciform joints of rectangular hollow section were fabricated with adhesive gusset plates (Fig. 8.15). Hollow sections of two different sizes were used, and some of the specimens were subjected to accelerated ageing prior to testing in tension. The structural behaviour of these joints was also predicted by non-linear, three-dimensional, finite-element analysis. Very good agreement was obtained between the experimental and predicted load-displacement behaviour. 

Mitchell, R.A., R.M. Woolley, and S.M. Baker, Finite Element Analysis of Spotwelded Bonded and Weldbonded Lap Joints, National Bureau of Standards, NBSIR 75-957, December 1975. 

Numerical methods (mainly finite element analysis) may be applied in principle in most cases. The practicality of using these methods should be considered separately for each design case. The subject of finite element analysis is not separately addressed for each joint configuration but it is discussed in general terms for each joint category. 

Guidelines for performing a finite element analysis of bonded joints are given in 5.S.2.2. 

P(9) The integrity and sufficiency of the joint shall be checked by testing the specimen. Ideally, for primary structural connections, this should be supplemented by finite element analysis. 

To determine Kffe from Equation (5.32), Kmesh and Kexp must be known. Kme is determined from a finite element analysis of the source model using rigid spring elements. Kexp is usually unknown and must be estimated from analytical or semi empirical models. There exist several semi-empirical expressions for the fastener flexibility (the inverse of the fastener stiffness Kexp) which are used in the industry. Those presented by Huth (reference 5.12) are valid for both metallic and composite (carbon FRF) members. The fastener flexibility for a single-lap joint from (reference 5.12) is ... 

In an effort to track evolution of failure in glued joints, Gozdecki and Smardzewski [2005] combined finite element analysis of stress distributions with AE event counts. They observed characteristic regions of crack growth that produced AE bursts, and they showed an exponential relationship between AE counts and the tangential stresses that arise during loading of the bond line. 

The finite element (FE) technique is an approximate numerical method for solving differential equations. Within the field of adhesive technology, it is most commonly used to determine the state of stress and strain within a bonded joint. It can also be used to determine moisture diffusion, natural frequencies of vibration and other field problems. Although this article will concentrate on the stress analysis, the same concepts can be applied to these other applications of finite element analysis. The basis of any finite element method is the discretization of the (irregular) region of interest into a number of... 

Adams, Coppendale and Peppiatt have applied elastic Finite-element analysis to the joint. Figure 2 gives some typical results. The bonded area comprises two different regions. First, in the central region, the shear stress is zero and the tensile stresses are uniform, the radial and circumferential og stresses being the same and related to the given axial stress by... 

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