Rim Chtourou, Nicolas Leconte, Bassem Zouari, Fahmi Chaari, Eric Markiewicz and Bertrand Langrand
This paper aims to propose a macro modeling approach to simulate the mechanical behavior and the failure of spot welded joints in structural crashworthiness computations.
Abstract
Purpose
This paper aims to propose a macro modeling approach to simulate the mechanical behavior and the failure of spot welded joints in structural crashworthiness computations.
Design/methodology/approach
A connector element is proposed to simulate the behavior and failure of spot weld joints. An elastic-plastic damageable model is used to describe the non-linear response and rupture. The connector model involves several parameters that have to be defined. Some are directly identified based on mechanical interpretations and experimental tests characteristics. The remaining parameters are identified through a finite element model updating approach using Arcan tests. Resulting from a sensitivity analysis, an original two steps optimization methodology, using the Modes I and II Arcan tests results sequentially, has been implemented to identify the remaining model parameters.
Findings
The numerical results for Arcan tests in mixed Modes I/II are in a good agreement with the experimental ones. The model is also validated on tensile pull-out, single lap shear and coach-peel tests.
Originality/value
By comparison with previous published results, the proposed model brings a significant improvement. The main innovative aspects of this work are as follows: the proposed formulation, a reduced number of parameters to optimize, an original sequential optimization methodology based on physical and mechanical analyses and a mesh size independent connector element.
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Keywords
Waseem Arif, Hakim Naceur, Sajjad Miran, Nicolas Leconte and Eric Markiewicz
The purpose of this study is to develop an elasto-plastic multi-material shell model by which finite element analysis of laser welded joints is carried out at the interface of the…
Abstract
Purpose
The purpose of this study is to develop an elasto-plastic multi-material shell model by which finite element analysis of laser welded joints is carried out at the interface of the heat-affected zone and base material.
Design/methodology/approach
The multi-material shell model is implemented on the simple cantilever and double cantilever welded plates to examine the efficiency of the developed model.
Findings
By reducing the computational time approximately 20 times with the developed model, the results obtained in the form of von Mises stress and equivalent plastic strain are found in good agreement as compared with the reference solid model.
Originality/value
The accurate and fast prediction of the stresses and strains in the laser welded joints, and the developed multi-material model is helpful to simulate complex industrial welded structures.
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Richard F. Kenny and Eileen Schroeder
Compact disk database systems have been proliferating in libraries for the past several years. Producers have promoted them as user‐friendly, self‐instructional systems that…
Abstract
Compact disk database systems have been proliferating in libraries for the past several years. Producers have promoted them as user‐friendly, self‐instructional systems that require little on‐site assistance for use. Libraries have placed the systems out for use and have sometimes found this assumption questionable. Numerous articles have appeared on planning for these new reference tools, but only a few have presented evaluations of their implementation and impact on librarians and library services (e.g., Lynn and Bacsany, 1989; Schultz and Salomon, 1990; Welsh, 1989; Steffy and Meyer, 1989; Nissley, et al., 1989; LePoer and Mularski, 1989; Nash and Wilson, 1991). Most have used user surveys to garner data on user satisfaction and effectiveness. Such questionnaires have tended to indicate favorable user reaction to the systems and to the relevance to their needs of the retrieved citations (e.g., Pope, 1989; Bleeker, Tjiam, and Volkers, 1988) while others have shown the former but not the latter phenomenon. Nash and Wilson (1991) found that students were satisfied with their searches but that over one‐third retrieved relatively useless or inappropriate citations. They found the undergraduates they surveyed and/or interviewed had problems critically analyzing the results of their searches. Stewart and Olsen (1988) conducted an experimental comparison of ERIC on CD‐ROM (SilverPlatter) and in print form. Subjects using the CD‐ROM outperformed those using the print index in retrieving relevant references for assigned topics. One particularly interesting result showed subjects using CD‐ROM with no prior training outperforming subjects trained to use print indexes. Further, regardless of treatment group membership, 90 percent felt that the CD‐ROMs would yield the greatest number of useful references. Both instructed and uninstructed CD‐ROM groups rated their methods as easier than print indexes.
The following is an annotated list of materials that discuss the ways in which librarians can provide library users with orientation to facilities and services, and instruct them…
Abstract
The following is an annotated list of materials that discuss the ways in which librarians can provide library users with orientation to facilities and services, and instruct them in library information and computer skills. This is RSR's 11th annual review of this literature, and covers publications from 1984. A few items from 1983 have been included because of their significance, and because they were not available for review last year. Several items were not annotated because the compiler was unable to secure them.
The following bibliography focuses mainly on programs which can run on IBM microcomputers and compatibles under the operating system PC DOS/MS DOS, and which can be used in online…
Abstract
The following bibliography focuses mainly on programs which can run on IBM microcomputers and compatibles under the operating system PC DOS/MS DOS, and which can be used in online information and documentation work. They fall into the following categories:
Elizabeth Koschmann, James L. Abelson, Amy M. Kilbourne, Shawna N. Smith, Kate Fitzgerald and Anna Pasternak
Mood and anxiety disorders affect 20–30 percent of school-age children, contributing to academic failure, substance abuse, and adult psychopathology, with immense social and…
Abstract
Purpose
Mood and anxiety disorders affect 20–30 percent of school-age children, contributing to academic failure, substance abuse, and adult psychopathology, with immense social and economic impact. These disorders are treatable, but only a fraction of students in need have access to evidence-based treatment practices (EBPs). Access could be substantially increased if school professionals were trained to identify students at risk and deliver EBPs in the context of school-based support services. However, current training for school professionals is largely ineffective because it lacks follow-up supported practice, an essential element for producing lasting behavioral change. The paper aims to discuss these issues.
Design/methodology/approach
In this pilot feasibility study, the authors explored whether a coaching-based implementation strategy could be used to integrate common elements of evidence-based cognitive behavioral therapy (CBT) into schools. The strategy incorporated didactic training in CBT for school professionals followed by coaching from an expert during co-facilitation of CBT groups offered to students.
Findings
In total, 17 school professionals in nine high schools with significant cultural and socioe-conomic diversity participated, serving 105 students. School professionals were assessed for changes in confidence in CBT delivery, frequency of generalized use of CBT skills and attitudes about the utility of CBT for the school setting. Students were assessed for symptom improvement. The school professionals showed increased confidence in, utilization of, and attitudes toward CBT. Student participants showed significant reductions in depression and anxiety symptoms pre- to post-group.
Originality/value
These findings support the feasibility and potential impact of a coaching-based implementation strategy for school settings, as well as student symptom improvement associated with receipt of school-delivered CBT.
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Tien-Wen Sung and Ting-Ting Wu
Learners were provided with personalized and adaptive articles in a dynamic real-time manner. This study aims to improve learners’ interest in learning English and motivate them…
Abstract
Purpose
Learners were provided with personalized and adaptive articles in a dynamic real-time manner. This study aims to improve learners’ interest in learning English and motivate them through an appropriate e-book assistance mechanism, thus increasing their English reading–comprehension skills.
Design/methodology/approach
In addition to their general auxiliary functions, e-books were designed to provide other relevant auxiliary functions to meet the English reading–learning requirements. The e-book was also equipped with a personalized reading guidance and assistance mechanism for conducting systematic assessments and calculations on the basis of the learner’s reading comprehension skills, article difficulty and difficulty stratification and connections between articles.
Findings
The personalized reading guidance and assistance strategy, which provided articles in line with the learners’ personal abilities and presented the articles in a correlated method, facilitated learners’ progressive learning and improved their reading–comprehension abilities. Learners’ confidence and satisfaction toward English reading can be improved effectively through adaptive guidance.
Originality/value
A real-time and dynamic reading guidance strategy was established in this study by considering the learner’s reading–comprehension skills, article difficulty and difficulty stratification and the connections between articles.
Details
Keywords
Melany Hebles, Concepción Yaniz-Álvarez-de-Eulate and Mauricio Jara
The purpose of this paper is to analyze the impact of a classroom application of the cooperative learning (CL) methodology on nine dimensions of business students’ teamwork…
Abstract
Purpose
The purpose of this paper is to analyze the impact of a classroom application of the cooperative learning (CL) methodology on nine dimensions of business students’ teamwork competence (TC).
Design/methodology/approach
The authors used a quasi-experimental pre-post design with a previous cohort as control group (first-year students from the year prior to treatment application), applying treatment to a sample of 228 first-year students in a School of Economics and Business at a Chilean University (114 as treatment and 114 as control).
Findings
The authors’ results show that CL had a positive, significant influence on five dimensions of TC: collective efficacy, planning, goal setting, problem solving and conflict management.
Research limitations/implications
This paper upholds the importance and effectiveness of CL in developing TC. However, the evidence suggests that the effectiveness of the CL methodology was limited to development and improvement of less complex dimensions of TC. More complex dimensions require a longer period of time to be developed.
Practical implications
This research is an important contribution to the design and implementation of appropriate methodologies for developing a widely needed area of competence in the workplace, considering its multidimensional nature, whether in academia or business.
Originality/value
This is the first study to seek empirical evidence that would link the CL methodology with TC. In addition, it fills a gap in the literature on the development of TC in its multiple dimensions. It particularly addresses the training of business professionals.
Propósito
El objetivo principal de este trabajo es analizar el impacto de la metodología Aprendizaje Cooperativo aplicada en aula en nueve dimensiones de la Competencia Trabajo en Equipo en estudiantes de negocios.
Diseño/Metodología/Enfoque
Se ha empleado un diseño cuasi experimental pre-post test con grupo cuasi control en una cohorte anterior (curso de primer año del año previo a la aplicación del tratamiento), aplicada a 228 estudiantes de 1° año de una Facultad de Economía y Negocios de una Universidad Chilena (114 de tratamiento y 114 de control).
Resultados
Los resultados obtenidos ponen de manifiesto un efecto positivo y significativo de la metodología Aprendizaje Cooperativo sobre cinco dimensiones de la Competencia Trabajo en Equipo, las cuales son eficacia colectiva, planificación, establecimiento de objetivos, resolución de problemas, y gestión de conflictos.
Limitaciones/Implicancias
El presente trabajo sostiene la importancia de emplear una metodología de Aprendizaje Cooperativo en la formación de la Competencia Trabajo en Equipo. No obstante, la evidencia presentada sugiere que la aplicación de la metodología Aprendizaje Cooperativo es significativa para dimensiones de menor complejidad en su desarrollo, ya que aquellas más complejas requieren de un horizonte más largo para ser adquiridas.
Implicancias prácticas
Esta investigación supone una contribución importante para el diseño e implementación de metodologías adecuadas para la formación de una competencia ampliamente requerida en el mundo profesional, considerando su carácter multidimensional, tanto en el ámbito universitario como empresarial.
Originalidad/Valor
Es el primer estudio que busca evidencia empírica acerca de la relación entre la aplicación de una metodología de Aprendizaje Cooperativo y la Competencia Trabajo en Equipo. Adicionalmente, complementa un vacío en la literatura a la formación de la Competencia Trabajo en Equipo desde sus múltiples dimensiones. En especial, en la formación de profesionales de los negocios.