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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.

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.

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.

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.

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.

The multi-material shell model is implemented on the simple cantilever and double cantilever welded plates to examine the efficiency of the developed model.

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.

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.

The riveting process is a metal forming process involving complex elastic-plastic deformation, which will induce a compressive residual stress field and cause local distortions in the connecting areas. Regarding to the aircraft panel assemblies with plenty of rivets, the global deformation is inevitable and undesired, leading difficulties to downstream assembly processes. This paper aims to present a new method for the local distortion calculation and the global deformation prediction of sheet panel assemblies during the automated riveting process.

In this paper, a simplified algebraic study is presented to analyze the local distortion of single countersunk rivet joint with the consideration of the barrel-like shape of the driven head and the through-thickness variations along the rivet shank. Then, an equivalent rivet unit is proposed based on the result of the algebraic study and embedded into the global-level model for the prediction of the overall distortions of riveted panels.

The algebraic study is able to reach a more precise contour of the deformed rivet than the traditional assumption of cylindrical deformations and rapidly determine the equivalent coefficients of the riveting unit. The result also shows an industrial acceptable accuracy of the prediction for the global deformations of the double-layered panel assemblies widely used in the aircraft panel structures.

A new local-global method for predicting the deformations of the riveted panel assembly based on the algebraic study of the local distortions is proposed to help the engineers in the early design stages or in the assembly process planning stage.

Large structures (e.g. plane, bridge, etc.) often include several hundreds of assembly points. Structural computations often use over-simplistic approximations for these points; among others, they do not take into account the thermo-mechanical history due to the assembling process. Running computations with each assembly point modelled completely would require too much time to achieve a simulation. There is thus a need to create equivalent elements for assembly points in order to: take into account the mechanical state of the assembly point in the design stage – while reducing the computational time cost at the same time. This paper aims to discuss these issues.

This paper introduces an innovative strategy based on a coupling procedure between a finite element tool for modelling the assembly process in order to access to the mechanical state of the assembly point and an optimisation algorithm, in order to identify the equivalent element parameters.

The strategy has proven to be successful. A connector model easier to use and much faster than the complete model, has been obtained. Results obtained with this element are in good agreement with experimental tests in the case of multipoint assemblies and with the simulation results of the complete numerical model. Finally the connector model appears to be easier to use and much faster than the complete model, more difficult to model properly.

The main innovative aspects of this strategy lie in the fact that the creation of this equivalent element is based on a complete numerical approach. The thermo-mechanical history due to the assembly process is considered – the element parameters are identified thanks to an evolution strategy based on the coupling between a finite element model and a zero-order minimisation algorithm.

In conditions where a product is subjected to extreme mechanical loading in a very short time, a strain rate has a significant influence on the behaviour of the product’s material. To accurately simulate the behaviour of the material during these loading conditions, the strain rate parameters of the selected material model should be appropriately used. This paper aims to present a fast method with which the proper strain-rate-dependent parameter values of the selected material model can be easily determined.

In the paper, an experiment was designed to study the behaviour of thin, flat, metal sheets during an impact. The results from this experiment were the basis for the determination of the strain-rate-dependent parameter values of the Cowper–Symonds material model. Optimisation processes with different numbers of required parameters of the selected material model were performed. The optimisation process consists of the method for design of experiment, modelling a response surface and a genetic algorithm.

The paper provides comparison of two optimisation processes with different methods for design of experiment. The performances of the presented method are compared and the engineering applicability of the results is discussed.

This paper presents a new fast approach for the identification of the parameter values of the Cowper–Symonds material model, if these cannot be easily determined directly from experimental data.

This paper relays the process the authors used to develop a monitoring and evaluation (M&E) framework in the emergency services team at Australian Red Cross. The paper aims to provide useful information and guidance to support others to build and improve their M&E frameworks, which are fundamental for guiding achievement of department or organisational goals.

This paper uses a case study to describe the participatory agile methodology applied to develop the framework. The completed framework includes indicators mined from pre-existing literature and highlights the benefits of using an agile and participatory approach to cultivate user buy-in, enhance operational relevance and create timely results.

Development of the M&E framework streamlined measurement across the team, improved programmatic strategic alignment, identified gaps in data collection and promoted utilisation of evaluative information. Additionally, it was an exercise in evaluation capacity building, with many process uses, which positively influenced the implementation stage.

There are very few scholarly papers that outline the process taken to develop M&E frameworks, and none in the humanitarian, emergency services field. Additionally, this paper offers an innovative use of agile in facilitating a collaborative, sustainable and meaningful framework.

The riveting with blind rivets is extensively used in railway structures, which are mainly composed of aluminium. The lack of knowledge in this process makes the railway constructors to over‐proportion the number of rivets used in the structures and to perform a lot of tests in order to validate them. To better understand the different phenomena occurring during this process, a numerical model has been made, based on experimental tests. Considering the diversity of assemblies found in a railway structure (various diameter values of rivet, thickness and multiple materials of sheet metal assemblies, etc.), we propose a methodology based on the simulation of their behaviour. The numerical model allows to avoid high characterisation costs based only on experience.

Expansion of large international hotel chains into the Polish hospitality market has radically changed hotel management practices in Poland. The article investigates the impact of these changes on hotels’ economic performance. This impact is assessed by monitoring changes in the break‐even point, the percentage share of variable costs in sales, margins of safety, operating leverage, and other indicators reflecting economic effects of applied management methods. The research results indicate that cost reduction resulting from the introduction of new management methods must in the future be replaced by measures aimed at stimulating revenue growth.

This research examines stock traders' disposition effects and contrarian/momentum behavior in the Taiwan Stock Exchange (TWSE). Specifically, we first investigate disposition effects across all trader types and then examine the relationships between disposition effects, trader types, and order characteristics. Next, we explore contrarian and/or momentum behavior and analyze the relationships among the contrarian/momentum behavior, investor type, and order characteristics. Finally, the links among trader types, order characteristics, and investment performance are detected. This chapter yields the following findings. (1) Individual investors exhibit the strongest disposition effects compared to other investors. (2) Foreign investors, investment trusts, and individual investors tend to use large orders to sell loser stocks. (3) Investment trusts are inclined to be momentum traders, while individual investors tend to perform contrarian strategies. (4) Institutional aggressive and large orders perform better than individuals' orders. (5) The performance of foreign investors' selling decisions is better than that of retail investors.

Rigid multibody modelling is used to study the crash‐related global behaviour of transport vehicles. These models are made up rigid bodies, joints and springs. Distinct kinematic models have been developed in order to analytically determine the resistance to collapse of thin‐walled structures of simple geometry subjected to compression or bending loading. The modeller must position these different elements but has no information on their numbers and their locations. For this reason, a modelling aiding tool, based on the elastic buckling analysis, has been developed. This method is used to resolve a problem of an “S” frame undergoing a collision against a rigid block to estimate its validity.