Self Piercing Riveting for Metal-Polymer Joints

Self-Piercing Riveting (SPR) is a sheet metal joining technique based on the insertion of a rivet into two or more sheets, with no preparatory hole. This process has gained wide diffusion in the automotive industry, due to the increasing use of materials alternative to steel, that are difficult or impossible to join with traditional techniques. In particular, polymeric materials are becoming increasingly used, due to their favorable weight/strength ratio. This paper reports the results of experimental investigations, aimed at identifying the variables affecting the mechanical characteristics of mixed metal-plastic joints. A statistic model for the optimization of the geometrical parameters has been computed. The paper demonstrates that self-piercing riveting appears competitive for metal/polymer junction. The results analyzed in light of statistical techniques show that some geometrical parameters affect joint performance more than others and can therefore be used as independent variables for joint performance optimizatio

Stamina of a non-gasketed flange joint under combined internal pressure and axial loading

The performance of a bolted flange joint is characterized mainly by its 'strength' and 'sealing capability'. A number of numerical and experimental studies have been conducted to study these characteristics under internal pressure loading conditions alone. However, limited work is found in the literature under conditions of combined internal pressure and axial loading. The effect of external, axial loading pressure being unknown, the optimal performance of the bolted flange joint cannot be achieved. Current design codes do not address the effects of axial loading on structural integrity and sealing ability. To study joint strength and sealing capability under combined loading conditions, an extensive experimental and numerical study of a non-gasketed flange joint was carried out. Actual joint load capacity was determined at both design and test stages with the maximum external axial loading that can be applied for safe joint performance. Experimental and numerical results have been compared and overall joint performance and behaviour is discussed in detail

Stamina of a non-gasketed flange joint under combined internal pressure, axial and bending loading : an experimental study

The performance of a bolted flange joint is characterized mainly by its 'strength' and 'sealing capability'. A number of numerical and experimental studies have been conducted to study these characteristics under internal pressure loading conditions alone. However, limited work is found in the literature under conditions of combined internal pressure and axial loading. The effect of external, axial loading pressure being unknown, the optimal performance of the bolted flange joint cannot be achieved. Current design codes do not address the effects of axial loading on structural integrity and sealing ability. To study joint strength and sealing capability under combined loading conditions, an extensive experimental and numerical study of a non¬gasketed flange joint was carried out. Actual joint load capacity was determined at both design and test stages with the maximum external axial loading that can be applied for safe joint performance. Experimental and numerical results have been compared and overall joint performance and behaviour is discussed in detail

Team Incentives and Reference-Dependent Preferences

This paper examines a multi-agent moral hazard model in which agents have expectation-based reference-dependent preferences `a la K˝oszegi and Rabin (2006, 2007). The agents’ utilities depend not only on their realized outcomes but also on the comparisons of their realized outcomes with their reference outcomes. Due to loss aversion, the agents have a first-order aversion to wage uncertainty. Thus, reducing their expected losses by partially compensating for their failure may be beneficial for the principal. When the agent is loss averse and the project is hard to achieve, the optimal contract is based on team incentives which exhibit either joint performance evaluation or relative performance evaluation. Our results provide a new insight: team incentives serve as a loss-sharing device among agents. This model can explain the empirical puzzle of why firms often pay a bonus to low-performance employees as well as high-performance employees.Moral Hazard, Team Incentives, Reference-Dependent Preferences, Loss Aversion, Joint Performance, Evaluation, Relative Performance Evaluation

Evaluating Wall Street Journal survey forecasters: a multivariate approach

This paper proposes a methodology for assessing the joint performance of multivariate forecasts of economic variables. The methodology is illustrated by comparing the rankings of forecasters by the Wall Street Journal with the authors’ alternative rankings. The results show that the methodology can provide useful insights as to the certainty of forecasts as well as the extent to which various forecasts are similar or different.Forecasting

Duty cycle testing and performance evaluation of the SM-229 teleoperator

The first known experimental studies and analyses of teleoperator performance for specific duty cycles are discussed. The results are presented in two distinct areas as position usage patterns, and as three-dimensional power grids. The position usage patterns are a valuable means to assess the available motion range. The power grids are a unique concept for evaluating joint performance. Final conclusions contain recommendations to upgrade the teleoperator for optimum performance

An Information Processing View on Joint Vendor Performance in Multi-Sourcing: The Role of the Guardian

This paper examines joint vendor performance in multi-sourcing arrangements. Using an Information Processing View, we argue that managing interdependencies between multiple vendors imposes substantial information processing (IP) requirements on clients. To achieve high joint performance, clients therefore need to possess sufficient IP capacity. We examine how three sources of IP capacity, two internal (i.e., the client's inter-vendor governance and the client's architectural knowledge) and one external (i.e., the guardian vendor), work together in realizing joint performance. Our results show that formal governance and architectural knowledge contribute to joint performance. The guardian vendor contributes to joint performance in settings where the client deploys strong governance but lacks architectural knowledge. This suggests that, contrary to common views in the literature, guardian vendors should not be understood as mediators (or single points of contact) who relieve clients from governance efforts. Instead, guardian vendors are more fruitfully understood as architects, who complement the client's governance efforts by compensating for knowledge gaps. Put simply, client firms should consider using a guardian vendor to compensate for weak architectural knowledge while still maintaining strong formal and informal governance of all vendors

Cooperative Radar and Communications Signaling: The Estimation and Information Theory Odd Couple

We investigate cooperative radar and communications signaling. While each system typically considers the other system a source of interference, by considering the radar and communications operations to be a single joint system, the performance of both systems can, under certain conditions, be improved by the existence of the other. As an initial demonstration, we focus on the radar as relay scenario and present an approach denoted multiuser detection radar (MUDR). A novel joint estimation and information theoretic bound formulation is constructed for a receiver that observes communications and radar return in the same frequency allocation. The joint performance bound is presented in terms of the communication rate and the estimation rate of the system.Comment: 6 pages, 2 figures, to be presented at 2014 IEEE Radar Conferenc

Analytical and statistical study on the effects of porosity level on weld joint performance Progress report

Correlation between porosity defects and mechanical behavior of weld joint

Bilateral, Collective, or Both? Formal Governance and Performance in Multisourcing

While multisourcing offers benefits such as access to best-of-breed resources and enhanced competition, it also presents clients with a new governance challenge, namely the need to ensure that vendors not only deliver their individual contributions but also collaborate to produce a coherent joint outcome. Clients can address this challenge by combining bilateral governance focused on each vendor’s individual performance with collective governance aimed at the vendors’ joint performance. However, it is unclear how the simultaneous application of bilateral and collective governance affects multisourcing performance. Indeed, the literature falls short in systematically differentiating these governance mechanisms and empirically examining their interplay. Drawing on existing work on multisourcing and on the outsourcing governance literature, we argue that bilateral and collective governance direct efforts toward different performance dimensions (individual vs. joint), invoke different metaphors (market vs. team), and promote conflicting norms (competitive vs. cooperative), which can result in trade-offs when bilateral and collective governance mechanisms are combined. Results from a survey of 189 multisourcing arrangements support our expectation that bilateral and collective governance promote different performance dimensions. Notably, one collective governance mechanism, conflict management procedures, contributes to both individual and joint performance. We find substitutional effects between bilateral and collective governance in relation to joint performance but not individual performance, indicating that the benefits of collective governance for joint performance are more easily compromised than the benefits of bilateral governance for individual performance. We also observe complementary effects within collective governance mechanisms. Our key contribution lies in theorizing and empirically examining the effects and interplay of bilateral and collective governance in multisourcing