Analysis of welding conditions based on induced thermal irreversibilities in welded structures: Cases of welding sequences and preheating treatment

AbstractPreheating treatment and employing a proper welding sequence are introduced as two efficient approaches for reducing residual stresses in welding processes. Selecting a right welding sequence and a proper preheating temperature for a weld system are crucial tasks, since welding residual stresses are inevitably produced in a welded structure. However, obtaining residual stresses is very complex, and much time is needed in some cases, particularly for the modeling and prediction of residual stresses in welded structures. So in this work, we attempt to show that these stresses depend on generated entropy during the arc welding process. Thus by obtaining thermal irreversibility effects from temperature distribution, due to a variation of different welding parameters, selection of optimum factors to achieve minimum residual stress is not only possible, but easier to undertake. In the proposed method, it is not a necessity to obtain residual stress values, and one can predict the behavior of residual stress qualitatively. To do so, 3D numerical models are employed to study the similar behavior of created residual stresses and entropy due to a variation of different preheating temperatures and three common welding sequences

A preliminary formal specification of virtual organization creation with RAISE specification language

Recently, several flavors of Formal Methods (FMs) have been gaining industrial acceptance and production quality software tools have begun emerging. Domain Engineering (DE) has been introduced as one of outstanding ideas in software development. It serves form al methods that provide a rigorous, mathematical based framework (domain model) for specifying, defining, and verifying systems in the software development. The increasing demands for extended products and services along with advances in IT industry have motivated researchers to create Virtual Organizations (VOs) in order to better respond to business opportunities and produce qualitative services and products. The purpose of this paper is to describe Virtual Organization and Domain engineering with introducing formal methods especially RAISE as a formal method that has been used successfully on diverse applications. Then, a primary formal model is presented using RAISE method and its language (RSL) formula for the improvement of VO creation process. Formal model presented in this paper is provable to implement. It improves reusability and reliability in such environments.Electrical Engineering, Mathematics and Computer Scienc

Experimentation of Rational Trust Evolution and Sustainability in Dynamic VOs

Part 10: Sustainability and TrustInternational audiencePiloted semi-automated mechanisms for monitoring and managing Virtual Organizations (VO) on the bases of established trust for collaboration that has already started need to be developed. Various researches in dynamic VOs have not established a semi-automated solution to manage the changing trustworthiness of the partners in the collaboration. The experimentation on semi-automated analysis of dynamic trustworthiness of VO indicates that a statistical standard deviation model promises more to be used to assess partners who sustained trust or failed to sustain trust in a period of time. This paper proposes a semi-automated TrustSEv (Trust Sustainability and Evolution) system for assessing partner’s trust sustainability in the VO during evolution phase. Further, the paper establishes a linear relationship between objective trust level of the individual partner constituting the VO, and the strength of the VO itself

A Novel Framework for Virtual Organization Creation on Cloud

Part 12: Collaboration PlatformsInternational audienceNowadays, virtual organizations (VOs) need to utilize new technologies in order to respond rapidly to collaboration opportunities. Cloud computing is a new paradigm that could leverage VO efficiency and flexibility whilst it could decrease VO expenditures and response time. Also, VO breeding environment (VBE) is an approach to create efficient VOs. Thus, combination of VBE and cloud computing may facilitate VOs creation and reactions to upcoming opportunities. This paper has proposed a framework to create VO on cloud environment, including three phases: creating and managing VBE on cloud, moving VBE on cloud and finally creating VO on cloud. The proposed framework may be considered as a solution to cope with VO requirements