TL;DR: In this paper, a new expression of stud load-slip relationship was put forward, and a calculation model of stud shear bearing capacity was proposed taking into account the influences of stud diameter and height, material strength, and elastic modulus.
Abstract: Stud shear connectors are the most widely used shear connectors in steel-concrete composite beams. The composite action of steel beam and concrete slab is effected by the stud shear properties directly. Thirty push-out tests on stud shear connectors were conducted to investigate the effects of stud diameter and height, concrete strength, stud welding technique, transverse reinforcement, and steel beam type on stud failure mode, load versus slip curve, and the shear bearing capacity. Based on the push-out test results, the stud shear mechanism was analyzed, a new expression of stud load-slip relationship was put forward, and a calculation model of stud shear bearing capacity was proposed taking into account the influences of stud diameter and height, material strength, and elastic modulus. Compared with existing models, the computed shear bearing capacities of the proposed calculation model had a better match with the experimental values.
TL;DR: The use of friction as an efficient thermo-mechanical source to both weld and process materials in the solid phase has come a long way since the first patent filing by Bevington in the late 19th Century as discussed by the authors.
Abstract: The utilisation of friction as an efficient thermo-mechanical source to both weld and process materials in the solid phase has come a long way since the first patent filing by Bevington in the late 19th Century. It is fair to say that up until the early Eighties, rotation was the primary motion used to practice friction welding for most applications on a commercial basis, certainly for metals. Work by Searle in the Seventies with orbital motion gathered momentum to permit the welding of non-round parts. This was followed by the development of a dedicated machine to use linear reciprocating motion for joining. From the late Eighties onwards an ‘explosion’ of friction based technologies were conceived and promoted. Such processes include friction taper stud and stitch welding, friction hydro pillar processing, friction extrusion, friction plunge welding, third-body friction welding and not least friction stir welding, which must be regarded as the major step change for the welding of aluminium and its alloys. Sandwiched between motion and process developments came more detailed studies of friction surfacing and friction seam welding, which were both the subject of a patent filing in 1941. The aforementioned processes are reviewed and selected processes discussed more fully. Attention is drawn to the applications, industrial sectors, etc., to which they can be aligned.
TL;DR: In this article, the self-manufacturing cost estimation, cost optimization and competitiveness of different composite floor systems: composite I beams, composite trusses produced from rolled channel sections, and composites made from cold formed hollow sections.
TL;DR: In this article, the effect of weld process parameters on weld defects, macrostructure and mechanical properties in AISI 4140 steel was considered and 3D residual stress data for a typical friction taper stud weld applied downwards force, rotational speed and plunge depth (equivalent to consumable length).
TL;DR: A semi-autonomous approach to robotic stud the welding with focus on the HRI (Human-Robot Interaction), carried out autonomously by an autonomous industrial mobile manipulator (AIMM).
Abstract: Ship construction is a major industry worldwide, and many tasks have been automated. One task that is still solely carried out manually is welding of studs. This paper presents a semi-autonomous approach to robotic stud the welding with focus on the HRI (Human-Robot Interaction). The welding itself is carried out autonomously by an autonomous industrial mobile manipulator (AIMM). An intuitive interface is proposed for the AIMM to ensure safe and correct operation. The interface allows non-expert operators to program, verify, and reprogram the robot's task on the manufacturing site. Task specific information is projected directly into object space as augmented reality using a projector mounted on the robot end-effector. Specifically, stud positions are shown on the ship wall before welding is initiated, and positions can be added, deleted, and moved using an IMU as pointing device. The contribution of this paper is an intuitive interface for on-site programming of stud welding robots; implemented in a skill-based task programming architecture. The system is designed and implemented, and proof-of-concept tests are presented.