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Fibre reinforced polymer composites (FRPs) are finding increasing usage in many industrial sectors. Adhesive bonding is often the most attractive joining technique for these materials in terms of structural efficiency and cost of manufacture. However, concerns regarding the lack of reliable design methods, the long term ageing behaviour and the difficulties in non‐destructive evaluation and repair of bonded joints has led to a reluctance to use adhesives in primary structures. DERA has been involved in the assessment of adhesive bonding for joining FRPs for many years. This paper focuses on investigations at DERA into the effects that environment and fatigue loading have on the performance of bonded composite joints, and briefly reviews current approaches to strength and lifetime prediction. It is seen that adhesively bonded composite joints can be significantly affected by the service environment, however, this is highly dependent on the joint type and materials involved.

This experiment examined the effects of motivational orientation (prosocial versus egoistic) on interpersonal trust, negotiation behavior, amount of impasses, and joint outcomes in three‐person negotiations. Students participated in a joint venture negotiation, in which motivational orientation was manipulated by allocating individual incentives (egoistic motive) vs. team incentives (prosocial motive). Results indicated that prosocially motivated negotiators achieved more integrative agreements and fewer impasses, and reported higher trust, more problem solving, and less contending behavior than egoistically motivated negotiators. Hierarchical regression suggested that the finding that prosocial groups achieved higher joint outcomes can be explained by higher levels of trust, more problem solving behavior, and less contending behavior in prosocial groups.

This paper aims to address the issue of model discontinuity typically encountered in traditional Denavit-Hartenberg (DH) models. To achieve this, we propose the use of a local Product of Exponentials (POE) approach. Additionally, a modified calibration model is presented which takes into account both kinematic errors and high-order joint-dependent kinematic errors. Both kinematic errors and high-order joint-dependent kinematic errors are analyzed to modify the model.

Robot positioning accuracy is critically important in high-speed and heavy-load manufacturing applications. One essential problem encountered in calibration of series robot is that the traditional methods only consider fitting kinematic errors, while ignoring joint-dependent kinematic errors.

Laguerre polynomials are chosen to fitting kinematic errors and high-order joint-dependent kinematic errors which can avoid the Runge phenomenon of curve fitting to a great extent. Levenberg–Marquard algorithm, which is insensitive to overparameterization and can effectively deal with redundant parameters, is used to quickly calibrate the modified model. Experiments on an EFFORT ER50 robot are implemented to validate the efficiency of the proposed method; compared with the Chebyshev polynomial calibration methods, the positioning accuracy is improved from 0.2301 to 0.2224 mm.

The results demonstrate the substantial improvement in the absolute positioning accuracy achieved by the proposed calibration methods on an industrial serial robot.

The purpose of this paper is to discuss an example of modelling with experiments of robot prototype with dependent joint concept, including a full description of related functionalities. Reduction in active degrees of freedom in a machine can lead to improved accuracy, improved reliability and lower cost. The reconfiguration of machines and systems is a key technology for future responsive manufacturing systems. The concept of dependent joints helps to implement much specified sub-workspaces depending on functional needs in the machine.

This is inherently made possible using smart mechanical concepts having embedded sensors and reconfigurable control systems. This paper introduces structural reconfiguration systems and discusses a sample approach to functional reconfiguration.

A successful manipulator design with extended features when considering reduction in active degrees of freedom in a machine would lead to specific sub-workspace with improved accuracy, improved reliability and lower cost.

Reduction in active degrees of freedom in a machine can lead not only towards a dedicated functional workspace but also towards improved accuracy, improved reliability and lower cost.

This paper is of value to engineers and researchers developing robotic manipulators for use in various aspects of industry.

This paper aims to examine whether emigration of high-skilled labor creates a positive effect in the home country by generating multi-country joint patent relationships between home and destination country-pairs.

A panel of data that uniquely captures the country of origin of patent applicants is used to assess if and how high-skilled emigration contributes to the prevalence of multi-country joint patents in a country. The analysis is conducted both in aggregate and across sub-samples based on the per capita income level of the home country. Finally, the role of absorptive capacity as a control variable is robustly considered.

Results suggest that emigration of high-skilled labor positively impacts the prevalence of multi-country joint patent ownership when emigration originates from middle- and high-income countries. Support for such “brain gain” via knowledge sharing in innovation is absent when high-skilled labor emigrates from low-income countries.

The analysis highlights a specific avenue by which the home country benefits from high-skilled emigration. It also provides comparative analysis across home countries of different income levels, which can provide insight into the external validity of papers using high-income country samples of innovative performance when assessing knowledge spillovers.

The main purpose of this paper is to approach the legal problems of mass privatisation in Poland. The authors present the structure of national investment funds which intend to be the experimental financial intermediaries in Poland. Their assets are quoted on the Stock Exchange in Warsaw from the beginning of May 1997. New and controversial roles of management firms are discussed in this paper.

Statistical analysis is based on annual data collected from 132 Boursa Kuwait listed firms from 2016 to 2019 (i.e. yielding 528 firm-year observations). During the observation window (i.e. 2016 to 2019) 116 firms switched from joint-to solo-audits. Level and change models test if audit quality (proxied by abnormal accruals) is impacted by joint-/solo-audit switching. Therefore this paper explores the audit quality following abolition of mandated joint-audits in Kuwait.

This paper investigates the impact on audit quality following abolition of mandated joint-audit requirements in 2016 in Kuwait. The study is differentiated from prior analysis by focusing on an emerging economy setting, and by considering a more expansive set of joint-audit pairings, solo-audit types and switching options.

Abolition of mandated joint-audit requirements prompted a majority of Boursa Kuwait listed firms to switch to solo-audits. Analysis indicates that switch does not significantly decrease audit quality. Also, audit quality changes are not dependent on the specific joint-audit pairing/solo-audit type switch.

Analysis is based on a single national setting comprising a small set of firms. Nonetheless, results imply the impact of joint-/solo-audit switching following abolition of mandated requirements is more universal with generalizability to different economic settings.

Results indicate that following elimination of mandated joint-audit requirements, firms have a propensity to favor solo-audits. Irrespective of the joint-audit pairing and solo-audit type, findings show a joint-/solo-audit switch does not compromise audit quality.

Analysis is the first to investigate the impact of joint/solo-audit switches on audit quality in an emerging economy with tests considering more joint-audit pairings than assessed previously.

This paper deals with experimental and numerical investigations of the composite behaviour within concrete-filled tubular columns with embedded massive steel core (CFTES columns). As the inner profile provides the main load-bearing capacity, the load introduction and transfer is of particular interest for the structural detailing of CFTES columns. Currently, no specific design regulations are available – neither for room temperature nor fire design. The presented investigations provide a basis for design recommendations and numerical approaches on reliable shear stresses.

Three series of push-out tests at room temperature and high temperatures are analysed in terms of ultimate shear strength, bond strength and shear strength-displacement-curve shape. The test parameters involve the steel core diameter and concrete cover, applying normal strength steel and concrete. Furthermore, a three-dimensional finite element model of the push-out tests is set up in Abaqus. The model implies temperature-dependent contact properties derived from the experimental tests using the cohesive behaviour method.

The test data reveal a distinctive reduction in both ultimate shear and bond strength for high temperatures. For high temperatures, the thermal expansion coefficients dominate the composite behaviour. Using the 3D numerical model and applying a temperature-dependent joint stiffness, maximum shear stress criterion and damage evolution, the observed composite behaviour can be described in a realistic manner.

The presented experimental investigations are unique, both concerning the investigated column type and performing push-out tests at high temperatures. For the first time, a temperature-dependent reduction of capable shear stresses is identified, which is crucial for the design of structural components.

The purpose of this paper is to describe the behavior of different lead-free solders (95.5Sn3.8Ag0.7Cu, i.e. SAC387 and Sn7In4.1Ag0.5Cu, i.e. SAC-In) in thermomechanically loaded non-collapsible ball grid array (BGA) joints of a low-temperature co-fired ceramic (LTCC) module. The validity of a modified Engelmaier’s model was tested to verify its capability to predict the characteristic lifetime of an LTCC module assembly implementable in field applications.

Five printed wiring board (PWB) assemblies, each carrying eight LTCC modules, were fabricated and exposed to a temperature cycling test over a −40 to 125°C temperature range to determine the characteristic lifetimes of interconnections in the LTCC module/PWB assemblies. The failure mechanisms of the test assemblies were verified using scanning acoustic microscopy, scanning electron microscopy (SEM) and field emission SEM investigation. A stress-dependent Engelmaier’s model, adjusted for plastic-core solder ball (PCSB) BGA structures, was used to predict the characteristic lifetimes of the assemblies.

Depending on the joint configuration, characteristic lifetimes of up to 1,920 cycles were achieved in the thermal cycling testing. The results showed that intergranular (creep) failures occurred primarily only in the joints containing Sn7In4.1Ag0.5Cu solder. Other primary failure mechanisms (mixed transgranular/intergranular, separation of the intermetallic compound/solder interface and cracking in the interface between the ceramic and metallization) were observed in the other joint configurations. The modified Engelmaier’s model was found to predict the lifetime of interconnections with good accuracy. The results confirmed the superiority of SAC-In solder over SAC in terms of reliability, and also proved that an air cavity structure of the module, which enhances its radio frequency (RF) performance, did not degrade the reliability of the second-level interconnections of the test assemblies.

This paper shows the superiority of SAC-In solder over SAC387 solder in terms of reliability and verifies the applicability of the modified Engelmaier’s model as an accurate lifetime prediction method for PCSB BGA structures for the presented LTCC packages for RF/microwave telecommunication applications.

The purpose of this paper is to propose a computational approach to establish the effect of various flow drilling screw (FS) process and material parameters on the quality and the mechanical performance of the resulting FS joints.

Toward that end, a sequence of three distinct computational analyses is developed. These analyses include: (a) finite-element modeling and simulations of the FS process; (b) determination of the mechanical properties of the resulting FS joints through the use of three-dimensional, continuum finite-element-based numerical simulations of various mechanical tests performed on the FS joints; and (c) determination, parameterization and validation of the constitutive relations for the simplified FS connectors, using the results obtained in (b) and the available experimental results. The availability of such connectors is mandatory in large-scale computational analyses of whole-vehicle crash or even in simulations of vehicle component manufacturing, e.g. car-body electro-coat paint-baking process. In such simulations, explicit three-dimensional representation of all FS joints is associated with a prohibitive computational cost.

Virtual testing of the shell components fastened using the joint connectors validated the ability of these line elements to realistically account for the strength, ductility and toughness of the three-dimensional FS joints.

The approach developed in the present work can be used, within an engineering-optimization procedure, to adjust the FS process and material parameters (design variables) in order to obtain a desired combination of the FS-joint mechanical properties (objective function).