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It has been verified that the WBZ‐α method of Wood, Bossak and Zienkiewicz can have unconditional stability and numerical dissipation for linear elastic systems. However, it is still unclear about its performance in the solution of nonlinear systems analytically. Hence, this study proposes to analytically investigate its numerical characteristics for solving nonlinear systems.

Two parameters are introduced to facilitate the basic analysis for nonlinear systems. One is the step degree of nonlinearity, which describes the stiffness change within a time step, and the other is the step degree of convergence, which describes the convergence error due to an iteration procedure.

It is theoretically proved that the sub‐family of WBZ‐α method of −1≤α<0, β=(1/4)(1−α)² and γ=(1/2)−α is unconditionally stable and has desired numerical dissipation for any nonlinear systems even with the presence of convergence error. These theoretical results are confirmed by numerical examples.

This analytical study reveals that the performance of the WBZ‐α method for nonlinear systems is in general the same as that for linear elastic systems.

Implicit and explicit time integration schemes in conjunction with the finite element method are presented for the transient response of highly non‐linear problems such as impact situations exhibiting important material dissipation. Surprisingly the implicit schemes lead to excellent convergence properties that make them a cost‐efficient alternative to explicit scheme generally advocated as the best choice for these problems. As numerical illustrations, we present here the academic impact between two flexible bodies, a long tube and a long plate, as well as a more industrial‐oriented application: the impact between a fan blade and a double casing.

A number of finite element formulations involving discontinuous weighting functions have been tested against analytic solutions for a steady scalar convection—diffusion problem at intermediate Peclet number, with a ‘hard’ downstream boundary condition. The emphasis is on extending these methods to isoparametric bilinear and biquadratic elements. In order to do this a procedure is given for the exact calculation of shape function Laplacians. Having confirmed the success of the Brooks—Hughes streamline upwind Petrov—Galerkin (SUPG) method for isoparametric bilinear elements, formulations for biquadratic elements are examined. Galerkin least squares offers little advantage over SUPG in the test problem. The generalized Galerkin method of Donea et al. gave excellent results, but because of concern over the possibility of cross‐streamline artificial diffusion in some cases, a strictly streamline formulation incorporating the optimal parameters of Donea et al. is proposed. This gave excellent results on a sufficiently refined mesh.

The numerical treatment of coupled field interaction problems frequently uses mixed time integration methods. These methods permit different time integration methods (implicit, explicit) and/or different timesteps to be used simultaneously in different parts of the mesh. This paper summarizes the various mixed time integration methods and provides a unified presentation. Computer implementation of the generalized scheme is provided through a 1D linear structural dynamics program (GEMIX). Two common examples illustrate the use of GEMIX program.

Wonders whether companies actually have employees best interests at heart across physical, mental and spiritual spheres. Posits that most organizations ignore their workforce – not even, in many cases, describing workers as assets! Describes many studies to back up this claim in theis work based on the 2002 Employment Research Unit Annual Conference, in Cardiff, Wales.

The purpose of this paper is to present a new stabilised low-order finite element methodology for large strain fast dynamics.

The numerical technique describing the motion is formulated upon the mixed set of first-order hyperbolic conservation laws already presented by Lee et al. (2013) where the main variables are the linear momentum, the deformation gradient tensor and the total energy. The mixed formulation is discretised using the standard explicit two-step Taylor-Galerkin (2TG) approach, which has been successfully employed in computational fluid dynamics (CFD). Unfortunately, the results display non-physical spurious (or hourglassing) modes, leading to the breakdown of the numerical scheme. For this reason, the 2TG methodology is further improved by means of two ingredients, namely a curl-free projection of the deformation gradient tensor and the inclusion of an additional stiffness stabilisation term.

A series of numerical examples are carried out drawing key comparisons between the proposed formulation and some other recently published numerical techniques.

Both velocities (or displacements) and stresses display the same rate of convergence, which proves ideal in the case of industrial applications where low-order discretisations tend to be preferred. The enhancements introduced in this paper enable the use of linear triangular (or bilinear quadrilateral) elements in two dimensional nearly incompressible dynamics applications without locking difficulties. In addition, an artificial viscosity term has been added into the formulation to eliminate the appearance of spurious oscillations in the vicinity of sharp spatial gradients induced by shocks.

The purpose of this paper is to apply the variational multi-scale framework to the finite element approximation of the compressible Navier-Stokes equations written in conservation form. Even though this formulation is relatively well known, some particular features that have been applied with great success in other flow problems are incorporated.

The orthogonal subgrid scales, the non-linear tracking of these subscales, and their time evolution are applied. Moreover, a systematic way to design the matrix of algorithmic parameters from the perspective of a Fourier analysis is given, and the adjoint of the non-linear operator including the volumetric part of the convective term is defined. Because the subgrid stabilization method works in the streamline direction, an anisotropic shock capturing method that keeps the diffusion unaltered in the direction of the streamlines, but modifies the crosswind diffusion is implemented. The artificial shock capturing diffusivity is calculated by using the orthogonal projection onto the finite element space of the gradient of the solution, instead of the common residual definition. Temporal derivatives are integrated in an explicit fashion.

Subsonic and supersonic numerical experiments show that including the orthogonal, dynamic, and the non-linear subscales improve the accuracy of the compressible formulation. The non-linearity introduced by the anisotropic shock capturing method has less effect in the convergence behavior to the steady state.

A complete investigation of the stabilized formulation of the compressible problem is addressed.

A simple modification of J2‐flow theory is made which enables it to approximately represent the reduced stiffness and increased plastic flow of corner‐theory response to non‐proportional loading. The key idea involves making the plastic modulus a function of the loading direction. A concise radial‐return type numerical algorithm is presented for the constitutive integration.

Purpose: The development of service automation continues to underpin the travel, tourism and hospitality sectors providing benefits for both customers and service companies. The purpose of this chapter is to showcase the practice of self-service technology (SST) usage in the contemporary tourism and hospitality sectors and present a conceptual framework of customer SST adoption.

Design/Methodology/Approach: This chapter offers an examination of theory, research and practice in relation to SST usage in tourism, highlighting the benefits and drawbacks arising for both customers and service providers. Since the benefits are achieved only if SSTs gain effective adoption with customers, this chapter focuses on concepts underpinning the study of customer SST adoption. Drawing on SST adoption factors and SST customer roles, a conceptual framework of SST adoption is discussed.

Findings/Practical Implications: This chapter examines the principles and practice underpinning the usage of self-service technologies in the travel, tourism and hospitality sectors, with specific reference to customer SST roles in co-creation. The customer SST roles provide a more detailed and nuanced picture of the customer perspective on SST usage. These nuanced roles are captured in a conceptual framework which seeks to further refine the understanding of customer SST adoption.

Research Implications & Originality/Value: The framework provides a useful foundation for further research with a focus on customer empowerment in SSTs. The future development of service automation will require a balance between the delivery of a personalised and smarter customer experience and technology applications that are unobtrusive and which do not pose any ethical or privacy concerns.

The chapter analyses the role of smart grid technology in the German energy transition. Information technologies promise to help integrate volatile renewable energies (wind and solar power) into the grid. Yet, the promise of intelligent infrastructures does not only extend to technological infrastructures, but also to market infrastructures. Smart grid technologies underpin and foster the design of a “smart” electricity market, where dispersed energy prosumers can adapt, in real time, to fluctuating price signals that register changes in electricity generation. This could neutralize fluctuations resulting from the increased share of renewables. To critically “think” the promise of smart infrastructure, it is not enough to just focus on digital devices. Rather, it becomes necessary to scrutinize economic assumptions about the “intelligence” of markets and the technopolitics of electricity market design. This chapter will first show the historical trajectory of the technopolitical promise of renewable energy as not only a more sustainable, but also a more democratic alternative to fossil and nuclear power, by looking at the affinities between market liberal and ecological critiques of centralized fossil and nuclear based energy systems. It will then elucidate the co-construction of smart grids and smart markets in the governmental plans for an “electricity market 2.0.” Finally, the chapter will show how smart grid and smart metering technology fosters new forms of economic agency like the domo oeconomicus. Such an economic formatting of smart grid technology, however, forecloses other ecologically prudent and politically progressive ways of constructing and engaging with intelligent infrastructures.