Papers by Keyword: Joint

Abstract: Industrial requirements to establish metallic joints between dissimilar metals in the electric area. The ultrasonic welding process is an optimal process to joint thin sheets or foils. The goal of the research was to optimize the ultrasonic welding parameters to join thin nickel-coated copper sheets and aluminium sheets. It used a 0.5 mm thick high-purity copper (Cu-OF-R200) sheet coated with a 10 μm pure nickel layer and a 0.5 mm thick aluminium (1050A H24) sheet. The ultrasonic welding is made by a Branson Ultraweld L20 ultrasonic welder equipment. The mechanical properties and exacting geometrical tolerance of the joint were required. The welding parameter optimization is made empirically, with several welding tests. The optimal welding parameters were confirmed by non-destructive and destructive tests of the joints. The non-destructive tests were the visual inspection and geometrical measurements of the joint sizes. The destructive tests were tensile tests and macroscopic and microscopic tests. The completed test results confirmed the process applicability and the quality of the joint.

Abstract: The work concerns the use of polyvinyl chloride joints as a modern method of stabilizing the trenches in military construction built on unstable water-saturated slopes by combining it with a transverse drainage. Employment of the method will reduce the hydrostatic pressure on the trench walls, excluding the possibility of collapse, and will increase the efficiency of service at military bases. Polyvinyl chloride joints are used in hydraulic engineering in a number of countries, in the construction of artificial canals, swimming pools and flood protection. The novelty of this method is its usage in flooded areas, which at the same time prevents landslides by organizing drainage.

Abstract: This paper compares the stress and strain behaviour of mechanical fasteners and elastic adhesive connections in timber façade applications. Two common designs with timber cladding are introduced. The traditional façade planks and multilayer large-format solid wood panels were selected. The resistance of a reference façade section with mechanical fasteners or adhesive bond to wind suction is determined according to the recommendations of European guideline ETAG 034. The pressure/suction chamber allowing hermetic closure was used. The sample deformation was measured at 15 locations, this also allowed to determine the elongation of the adhesive layer at break. The failure loads reached with the adhesive joint exceeded 20 kN/m² in both combinations of façade cladding. On the other hand, the sample with a large-format panel and mechanical fasteners showed the lowest failure load at 12 kN/m². The results confirmed that bonded joints are a suitable solution for large-format cladding, whereas an increase in the number of mechanical fasteners will be a more convenient solution for façade plank applications.

Abstract: A new method of linear connected joints (Ti/CF-plug/Epoxy) of Ti (Titanium) to Epoxy connected by CF-plug was innovated and developed, since fine carbon fibers (CFs) generate the extremely large friction force by their broad interface between metals and Epoxy polymer (M/Epoxy). Compared with glue and spontaneous adhesions of M/Glue/Epoxy and M/Epoxy, the new method remarkably improved the fracture toughness with maintaining light weight. To maintain the high joint strength of the Ti/CFW-CFJ/Epoxy, the Ni coating film on CF should control to bite the CF by molten Ti. The tensile strength (σ_b) and its strain (ε_b) of Ti/NiCFW-CFJ/Epoxy were higher than those of Ti/CFW-CFJ/Epoxy. In addition, increasing the CF-volume increases the σ_b. The CF-plug joint between Ti and Epoxy matrix CFRP apparently probably enhances the fuel efficiency, as well as safety level of airplane.

Abstract: Technique of determination of permissible compressive stresses in products made of anisotropic composite materials with holes in joints “parent sheet - stiffening element” is introduced. Besides, physical-mechanical properties and material load factor are taken into account. Finite-element model to determine stress strain behavior along the hole outline and in the ”field” points of composite material has been developed.

Abstract: In this paper, the results of the structural analysis of glued laminated timber and its joints in corrosive environment are shown. This paper includes calculation results for dowel connections of wood structures using steel and carbon fibres cylindrical dowel pins in accordance with the applicable regulatory documents by means of finite element analysis in ANSYS software, as well as experimental findings.

Abstract: The purpose of this study is to develop computational mathematical models for virtual prototyping of an actuation system from an exoskeleton human knee joint. These models are a part of the virtual and experimental prototype of a mechatronic system for locomotion rehabilitation in case of disabled persons. Experimental tests were performed on a group of persons without locomotion deficiencies. The obtained database was used to develop geometrical kinematic synthesis of the exoskeleton actuation mechanisms for knee’s joint and also ankle.

Abstract: Construction time becomes an important economical phenomenon, in last years in particular, which is comparable e.g. with consumption of materials. Construction and repair of bridges with a composite concrete slab may be accelerated by prefabrication. The joints of precast slab elements become then the weak places. Application of UHPC in joints solves this problem due to its excellent mechanical properties.

Abstract: Many aluminium structures contain welded and bolted connections that are modeled as one or more equivalent T-stubs – also referred to as tension zone components – for the structural assessment. Knowledge on the structural behavior of such T-stubs is thus essential for proper designs. However, this behavior has never been checked for fire conditions. In this paper, the structural behavior of aluminium T-stubs exposed to fire is studied through a combination of tests, finite element simulations, and theoretical models. A safe and conservative assessment procedure is developed for determining the critical temperature, based on the material deterioration as a function of temperature. This enables engineers and practitioners to determine a conservative value of the fire resistance.

Abstract: The bearing capacity of a scarf joint depends on the length of the joint and the type of connection. It is possible to use circular bolts or squared dowels. Both connection tools used in the repairs of historic timber structures are made of wood according to the requirements of the heritage authority.