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The purpose of this paper is to investigate the static behavior of different type of butt joints for application in a timber sofa furniture frame. In timber sofa structure, butt joints are commonly used between plywood and hardwood members but they are normally designed without any regard to the effect of grain directions of the wood members on the joint strength. The focus of the paper is to look at the effect of grain directions on the wooden member properties and on the strength of the butt joint in order to understand the failure mode to establish a more durable and effective sofa butt joint than the one normally used by the manufacturers.

Experiment tests are conducted to determine the mechanical properties of joint members, the maximum load‐carrying capacity of the butt joints, and the types of the failure in the joints in relation to different grain orientations under transverse loading conditions. Plywood and hardwood members are used in construction of the joint tests. Four types of butt joints are constructed with different condition of grain orientation, glue, and screw used in the joint members. The specimens are tested by fixing the plywood member and applying a transverse load to the hardwood member to simulate the conditions in the sofa frame.

Result shows that butt joint with vertical grain orientation and joint with two screws and glue have the maximum load‐carrying capacity compared to the other three cases and compared to the current joint type used in the existing sofa frame design.

The paper is of value to furniture manufacturing industry, in which furniture members and joints are usually over‐designed without regard to grain orientations or applying sound engineering techniques.

In order to connect a fiberglass composite structure to a steel structure, a hybrid composite made of glass and steel fibers has been studied. The hybrid composite has one end section with all glass fibers and the opposite end section with all steel fibers. As a result, it contains a transition section in the middle of the hybrid composite changing from glass fibers to steel fibers. The purpose of this paper is to examine interface strength at the glass to steel fiber transition section, in order to evaluate the effectiveness of the hybrid composite as a joining technique between a polymer composite structure and a metallic structure.

The present micromechanical study considers two types of glass to steel fiber joints: butt and overlap joints. For the butt joint, the end shape of the steel fiber is also modified to determine its effect on interface strength. The interface strength is predicted numerically based on the virtual crack closure technique to determine which joint is the strongest under various loading conditions such as tension, shear and bending. Numerical models include resin layers discretely. A virtual crack is considered inside the resin, at the resin/glass‐layer interface, and at the resin/steel‐layer interface. The crack is located at the critical regions of the joints.

Overall, the butt joint is stronger than the overlap joint regardless of loading types and directions. Furthermore, modification of an end shape of the middle fiber layers in the butt joint shifts the critical failure location.

The paper describes one of a few studies which investigated the interface strength of the hybrid joint made of fiberglass and steel‐fiber composites. This joint is important to connect a polymeric composite structure to a metallic structure without using conventional mechanical joints.

Presently, the materials used in light combat aircraft structures are aluminium alloys and composites. These structures are joined together through riveted joints. The weight of these rivets for the entire aircraft is nearly one ton. In addition to weight, the riveted connection requires a lot of tools, equipments, fixtures and manpower, which makes it an expensive and time-consuming process. Moreover, Al alloy is also welded using tungsten inert gas (TIG) welding process by proper control of process parameters. This process has limitations such as porosity, alloy segregation and hot cracking. To overcome the above limitations, an alternative technology is required. One such technology is friction stir welding (FSW), which can be successfully applied for welding of aluminium alloy in LCA structures. Therefore, this paper aims to compare the load carrying capabilities of FSW joints with TIG welded and riveted joints.

FSW joints and TIG welded joints were fabricated using optimized process parameters, followed by riveted joints using standard shop floor practice in the butt and lap joint configurations.

The load-carrying capabilities of FSW joints are superior than those of other joints. FSW joints exhibited 75 per cent higher load-carrying capability compared to the riveted joints and TIG-welded joints.

From this investigation, it is inferred that the FSW joint is suitable for the replacement of riveted joints in LCA and TIG-welded joints.

Friction stir butt joints exhibited 75 per cent higher load-carrying capability than riveted butt joints. Friction stir welded lap joints showed 70 per cent higher load-carrying capability than the riveted lap joints. Friction stir butt joints yielded 41 per cent higher breaking load capabilities than the TIG-welded butt joints. Moreover, Friction stir lap weld joints have 57 per cent more load-carrying capabilities than the TIG-welded lap joints.

This study investigates the fitting techniques for notch fatigue curves, seeking a more reliable method to predict the lifespan of welded structures.

Building on the fatigue test results of butt and cruciform joints, this research delves into the selection of fitting methods for the notch fatigue curve of welded joints. Both empirical formula and finite element methods (FEMs) were employed to assess the notch stress concentration factor at the toe and root of the two types of welded joints. Considering the mean stress correction and weld misalignment coefficients, the notch fatigue life curves were established using both direct and indirect methods.

An engineering example was employed to discern the differences between the direct and indirect approaches. The findings highlight the enhanced reliability of the indirect method for fitting the fatigue life curve.

While the notch stress approach is extensively adopted due to its accurate prediction of component fatigue life, most scholars have overlooked the importance of its curve fitting methods. Existing literature scantily addresses the establishment of these curves. This paper offers a focused examination of fatigue curve fitting techniques, delivering valuable perspectives on method selection.

Laser peening without coating (LPwC) is an innovative surface enhancement technology for introducing compressive residual stress in metallic materials. The purpose of this study is to examine the characteristic at the laser‐peened welded zone and the fatigue lives of the welding joints.

LPwC conditions for 490 MPa grades of structural steels were selected. By using the conditions, the characteristic at the laser‐peened welded zone, residual stresses, hardness and roughness of welding toes were examined. Moreover, the fatigue lives of the toes of box‐welded joints and butt welded joints pre‐treated by LPwC were compared to the fatigue lives of those that were not pre‐treated by LPwC.

The main results are: LPwC conditions for 490 MPa grade steels were established; residual stresses, Vickers hardness and roughness at the laser‐peened welded zone were revealed; and LPwC can dramatically extend the fatigue life of welded joint.

The effects of LPwC on structural steels, which are widely used in bridge members, have not been well clarified; the effect of LPwC on welded zones in these structures is particularly unclear. If LPwC can be carried out such that compressive residual stress is imparted on structural steels and the welded zones in the bridge members, the fatigue lives of bridge members will be greatly increased. The paper fills some of these gaps.

The use of synthetic resins as adhesives for metals or other non‐porous materials, in which there is increasing interest for structural and production reasons, imposes certain restrictions on the components bonded and the type of joint used. In the following paper the general points applicable to adhesive joints are first considered. A large number of strength measurements on simple light alloy lap joints made with ‘Araldite’ by the Eidg. Materialprüfungs und Versuchsanstalt (E.M.P.A.) are used to analyse the manner in which the breaking load under tensile shear loading depends on the geometry of the test specimen. It can be shown that in this special case, which is however of importance in practice, there is an optimum utilization both of the adhesive and of the metal, whose yield point determines the choice of sheet thickness and overlap. The use of synthetic resins as adhesives for metals and other non‐porous materials opens up numerous new developments and possibilities in a whole range of industries. Although comparatively new it has already found many practical applications which steadily increase.

THE first electron beam welder to be used in British airline maintenance is being installed at the Glamorgan plant of BOAC Engine Overhaul Ltd. The electron beam joins components without the distortion usual with conventional welding so it will be particularly appropriate applied in the re‐acrofoiling of jet engine stator blades. To accommodate a blade and its necessary fixtures, the suppliers, Hawker Siddeley Dynamics Engineering Ltd, have custom built the work chamber of the Dynaweld 6000, ensuring a complete welding cycle of only a few seconds.

Discusses the use of adhesives for structural bonding. Explores the range of adhesives available and how to make the correct application choice. Outlines the advantages and limitations of bonded joints, looking at the importance of joint design, surface preparation and application methods. Notes the need for a good quality control programme and gives examples of NDT apparatus that can be used to test the integrity of a joint. Concludes that new adhesive products are continually being developed for specific combinations of materials and application methods, enabling the designer to produce cheaper, better and environmentally friendlier products.

In order to extend the application of the original octagonal Goodman–Smith fatigue limit diagram, which is commonly used for the evaluation of structure fatigue stress in engineering, a modification of it is proposed for the structure made of S355 steel (commonly used in high-speed electric multiple units (EMUs) bogie frame).

The modification is made based on Deutscher Verband für Schweißen und verwandte Verfahren e. V. (DVS) 1612 standard and the γ-P-S-N curve, with consideration of the fatigue evaluation requirements of different survival rates and confidence levels. The verification of the modification is performed for three welded joints and for the comparison with the experimental data.

The results indicate that the design survival rate, the design safety margin and the fatigue stress evaluation of welded joint types are all improved by using the modified diagram.

There are relatively few studies on modifying octagonal Goodman–Smith fatigue limit diagram. In this paper, a modified diagram is proposed and applied in order to ensure the safety and durability of key welded structures of rail vehicles.

The purpose of this paper is to present a review about sizing of joints, from the static and fatigue points of view. A discussion about advantages and disadvantages of each joining technology, among the ones mentioned above, will be presented.

Although many other aspects will be discussed, emphasis will be given to the joint fatigue behavior, and fatigue test results will be presented and discussed.

This paper is a subject review, where no new findings are presented. However, the comparison of fatigue test results for mechanically fastened joints and friction stir welding joints will show the advantages of the latter.

With the information presented, the authors expect to provide some guidelines that will help to improve future joint designs.

The review information contained in this paper may be used as reference for aircraft joint design.