Search results for "Metalworking"

Design and use of a Fatigue Test Machine in Plane Bending for Composite Specimens and Bonded Joints

2011

Polymeric and composites materials are increasingly used in industry as structural parts, so that specific information on their mechanical properties "at long term" (creep, relaxation, fatigue) are requested. The design and implementation of these components also requires that they are permanently connected together to perform certain functions. The use of adhesives in structural joints has increased over recent years thanks to the continuous development by companies which provide the market with adhesive having better and better mechanical properties. The main areas relate to the aerospace, aeronautical and automotive industries, where requirements are required for lightness and reliabilit…

Raising the fatigue durability curves in case of the rehabilitation welding techniques

2018

Development of a Design Procedure for Bending Operations

1999

Springback can be considered as one of the most important shape defect in sheet stamping. Such effect results relevant even when simple bending operations are taken into account. In the paper the authors present a design procedure able to provide the proper value of the punch stroke to be applied in order to compensate for elastic springback. In particular two approaches have been followed: firstly an inverse design technique has been utilized in order to find out the response function governing the investigated phenomenon; furthermore neural network techniques have been applied in order to represent the logical link between the input data and the aimed output, i.e. the proper punch stroke …

Stress transfer mechanism investigation in hybrid steel trussed-concrete beams by push-out tests

2014

Abstract Results of push-out tests carried out on Hybrid Steel Trussed–Concrete Beams (HSTCBs) before and after the concrete casting are presented and interpreted. Firstly, in order to check the ability of weldings before casting, tensile tests were performed on specimens reproducing different types of welded joints. Simplified design formulae were used to predict their ultimate strength. Secondly, results obtained by push-out tests on specimen representative of the beam before and after the concrete casting are presented and discussed. Finally, simplified analytical models proposed by the current European building code were adapted to the specific typology to roughly predict the ultimate s…

On the analysis of Catalan thin vaults

2010

This paper is concerned with the identification, modelling and analysis of thin layered vaults, typical in the Catalan constructions of the XIX century. These special structures, also known as bovedas tabicadas, are characterized by very low thickness with respect to the medium surface dimensions and by the presence of different superimposed layers of bricks tied with mortar, are studied in order to individuate a coherent mechanical model for describing the material behaviour, to recognize the structural response utilizing as comparison adequate experimental results, and to extend the obtained results for the analysis of new vaults or for the restoration design of existing vaults. Firstly, …

Outlining the Limits of Friction Stir Consolidation as Used as an Aluminum Alloys Recycling Approach

2021

Friction stir consolidation (FSC) is a solid-state process that recycles metal scraps economically and eco-friendly compared to the conventional melting method. The process parameters especially processing time and rotational speed, have a crucial role in achieving a sound disc during FSC. The current study answers the research question of how far these process parameters can be effective when the mass of chips to be recycled increases. In specific, an experimental setup was analyzed that was previously identified as challenging for recycling 20 g chips of aluminum alloy AA 2024-O. Rotational speed was set doubled, and processing time was increased up to 1.5 times of their initial values. T…

Tērvetes pilskalna akmens lejamveidnes

2017

No analizētajām Tērvetes pilskalna 25 lejamveidnēm 2 ir pusfabrikāti. 10 veidnēs liets metāls, 11 bijusas nelietotas, 2 veidnēm lietosana nav nosakāma. 10 veidnes bija t.s. vāciņi - veidnes apģērba apsuvju un piekariņu aizmugures iegūsanai. Septiņas veidnes bijusas apvērsamās - ar ielietnēm akmens plāksnīsu augsā un apaksā. Akmens plāksnītes - lejamveidnes izgatavosanas procesā ir slīpētas un atsevisķos gadījumos pulētas. Veiddobumi pārsvarā izgriezti ar nazi.---The article analyses 25 finished and semi-manufactured stone casting moulds found at the hill-fort of Tērvete, dated to the 11th–13th century. In terms of construction they all are two-part moulds. Ten moulds have been used for cast…

The Relevance Of The Preform Design In Coining Processes Of Cupronickel Alloy

2007

Coining is a forging process in which a metallic disk, characterized by a low volume‐surface ratio, is deformed with the aim to impress 3D images on its three surfaces. Due to the large production volumes and, at the same time, to the high quality standards required to the final products in terms of final dimensions, tolerances and surface finishing, such closed‐die, cold forging process requires a careful evaluation and choice of the proper operative parameters. In particular, along with technological parameters as the die velocity, die stroke and lubrication, which, in turn, contribute to affect the pressure values on the die surfaces, and thus the press choice, geometrical parameters as …

Misfit evaluation of dental implant-supported metal frameworks manufactured with different techniques: Photoelastic and strain gauge measurements

2016

This study aims to compare in-vitro the fitting accuracy of implant-supported metal frameworks used for full-arch orthodontic restoration. The hypotheses tested were as follows: (1) for a fixed implant morphology, strains developed within the framework depend on how the framework had been fabricated and (2) stresses transferred to the implant–bone interface are related to the amount of framework misfit. Metal frameworks were fabricated using four different manufacturing techniques: conventional lost-wax casting, resin cement luting, electrospark erosion, and computer-aided design/computer-aided manufacturing milling. Each framework was instrumented with three strain gauges to measure strai…