Self-piercing riveting - a review

Self-Piercing Riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a semitubular rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requirement of joining lightweight materials, such as aluminium alloy structures, aluminium-steel structures and other mixed material structures, from the automotive industry. Compared with other conventional joining methods, SPR has a lot of advantages including no predrilled holes required, no fume, no spark and low noise, no surface treatment required, ability to join multilayer materials and mixed materials, and ability to produce joint with high static and fatigue strengths etc. This publication reviews research investigations that have been conducted in the area of self-piercing riveting. The process is described and the effects of the process parameters are discussed. Mechanical properties including static strength, fatigue and crash behaviour are reviewed. Corrosion behaviour is also addressed, while reliable methods for accurate behaviour prediction, process monitoring and non-destructive testing have been identified as the main challenges

Self-piercing riveting-a review

© The Author(s) 2017. This article is published with open access at Springerlink.com.Self-piercing riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR is currently the main joining method for aluminium and mixed-material lightweight automotive structures. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requirement of joining lightweight materials, such as aluminium alloy structures, aluminium-steel structures and other mixed-material structures, from the automotive industry. Compared with other conventional joining methods, SPR has many advantages including no pre-drilled holes required, no fume, no spark and low noise, no surface treatment required, ability to join multi-layer materials and mixed materials and ability to produce joints with high static and fatigue strengths. In this paper, research investigations that have been conducted on self-piercing riveting will be extensively reviewed. The current state and development of SPR process is reviewed and the influence of the key process parameters on joint quality is discussed. The mechanical properties of SPR joints, the corrosion behaviour of SPR joints, the distortion of SPR joints and the simulation of SPR process and joint performance are reviewed. Developing reliable simulation methods for SPR process and joint performance to reduce the need of physical testing has been identified as one of the main challenges.Peer reviewe

A review of challenges and opportunities of blockchain adoption for operational excellence in the UK automotive Industry

This paper aims to explore the challenges and opportunities of blockchain technology adoption from the lens of the TOE framework for operational excellence in the UK automotive industry context. The research methodology of this study follows a systematic review approach, which analyses existing academic published research papers in the top 35 academic journals. There was no specific timeframe established for this study and shortlisting the articles through a set of used keywords. A sample of 71 articles was shortlisted and analysed to provide a discussion on technological and management challenges and opportunities of blockchain adoption from the lens of the TOE framework for operational excellence. Findings– The findings of this study present significant theoretical and managerial implications and deep understanding for firms seeking to understand the challenges and opportunities of blockchain adoption for their operational excellence. Systematic literature approach was considered for the present study to explore existing academic papers on technological and management challenges and opportunities from the lens of TOE framework for operational excellence, whereas a more specified method meta-analysis can be considered for future research. The study has been explored in the UK automotive industry context, which has been considered as the limitation of generalization across countries and industries. This paper represents the most comprehensive literature study related to the technological and management challenges and opportunities of blockchain from the TOE framework angle for operational excellence.N/

OPTIMIZED FATIGUE AND FRACTURE PERFORMANCE OF FRICTION STIR WELDED ALUMINIUM PLATE: A STUDY OF THE INTER-RELATIONSHIP BETWEEN PROCESS PARAMETERS, TMAZ, MICROSTRUCTURE, DEFECT POPULATION AND PERFORMANCE

Friction stir welding (FSW) is an exciting new solid-state welding process with the potential to advantageously impact many fabrication industries. Current take-up of the process by industry is hindered by lack of knowledge of suitable welding parameters for any particular alloy and sheet thickness. The FSW process parameters are usually chosen empirically and their success is evaluated via simple mechanical property testing. There are severe drawbacks with such methods of determining manufacturing conditions. These include indirect relationships between tensile and fatigue properties, particularly for welds, and a high probability of totally missing real optimized conditions. This research is therefore undertaken as a first step in providing information that will assist manufacturing industry to make sound decisions with respect to selecting FSW parameters for weldable structural alloys. Some of the key issues driving material selection for manufacturing are weld quality in terms of defects, fatigue strength and crack growth, and fracture toughness. Currently a very limited amount of data exists regarding these mechanical properties of FSW welds, and even less information exists regarding process parameter optimization. This is due to the mechanical microstructural complexity of the process and the relatively large number of process parameters (feed, speed, force and temperature) that could influence weld properties. In order to advance predictive understanding and modeling for FS welds, it is necessary to develop force and energy based models that reflect the underlying nature of the thermo-mechanical processes that the material experiences during welding. This project aims at determining the influence and effect of Friction Stir Welding process control parameters on the microstructure of the thermo-mechanically affected zone, the defect population in the weld nugget, hardness, residual stresses, tensile and fatigue performance of 6 mm plate of 5083-H321 aluminium alloy, which is known to be susceptible to planar defect formation. Welds were made with a variety of process parameters (that is feed rate and rotational speed) to create different rates of heat input. Forces on the FSW tool (horizontal and vertical), torque and tool temperature were measured continuously during welding from an instrumented FSW tool. Detailed information on fatigue performance, residual stress states, microstructure, defect occurrence, energy input and weld process conditions, were investigated using regression models and contour maps which offer a unique opportunity to gain fundamental insight into the process-structure-property relationships for FS welds. Weld residual strains have been extensively measured using synchrotron X-ray diffraction strain scanning to relate peak residual stresses and the widths of the peak profiles, taken from a single line scan from the mid depth of the FS welds, with the weld process conditions and energy input into the welds. Several residual stress maps were also investigated. The optical and scanning electron microscope were used to determine the type of intrinsic defects present in the FSW fatigue and tensile specimens. Vickers hardness measurements were taken from the mid depth of the welds and were compared with the weld input parameters. The main contribution of this thesis is as follow: (i) the relationship between input parameters and process parameters; (ii) the relationship between input weld parameters (that is feed rate and rotational speed) and process parameters (that is vertical downwards force Fz, tool temperature, tool torque and the force footprint data), energy input and tensile strength, fatigue life and residual stresses to obtain regions of optimum weld conditions; (iii) identification of the defects present in FSW, their relationship with process parameters and their effect on tensile strength and fatigue life; and (iv) the usefulness of the real time process parameter monitoring automated instrumented FSW tool to predict the mechanical properties of the welds.Nelson Mandela Metropolitan University, South Afric

The impediments to the adoption of the design and build project procurement strategy in the Saudi construction industry

In the fast moving world with open international markets, the timely completion of construction projects within a stipulated budget will be of the highest priority. It can take months, years, and even decades to plan, design, procure, construct and handover a project to the client. Delays can mean failure. Similar to other parts of the world, the Saudi construction industry is being increasingly challenged to provide for faster, more economical and better construction. Clients are looking for new innovative methods that will shorten the project duration, meet the established budget and achieve the desired quality level. Design and Build (D&B) project procurement strategy appears to present a viable option. Whilst the benefits of D&B contracting have been directly realized in many industries for procuring various projects in many parts of the world, the Saudi construction industry has been slow to accept the D&B option. The D&B project delivery option has not been adopted on a grand scale and its application is still limited. The traditional design, bid, build (D.B.B) project delivery option still dominates the local Saudi construction industry. On a close examination, there appears to be impediments preventing the adoption of D&B contracting within the Saudi construction industry. This study will investigate and define these impediments and propose practical recommendations to overcome them. To investigate this problem and discover these practical solutions, a mixed methodology approach is employed. Both quantitative and qualitative data from surveys and direct interviews have been gathered. The interviews were conducted with key participants representing consulting and contracting firms, manufacturers, developers, public and private sector clients, financial market evaluators, and insurance firms. To enrich the investigation, a pertinent case study for a university campus which was procured along the D&B option is also examined. The main findings are reported with a set of recommendation. The results suggest that local industry stakeholders are divided or undecided on the benefits of D&B and its appropriateness. The nature of these impediments are cultural, lack of knowledge about D&B option, a scarcity of medium size D&B firms, and current government contracts which are based on the traditional D.B.B delivery option. Recommendations to improve the performance and productivity utilizing D&B are presented including a practical guidelines model to be consulted by D&B clients

Strategic Latency Unleashed: The Role of Technology in a Revisionist Global Order and the Implications for Special Operations Forces

The article of record may be found at https://cgsr.llnl.govThis work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344. The views and opinions of the author expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC. ISBN-978-1-952565-07-6 LCCN-2021901137 LLNL-BOOK-818513 TID-59693This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344. The views and opinions of the author expressed herein do not necessarily state or reflect those of the United States government or Lawrence Livermore National Security, LLC. ISBN-978-1-952565-07-6 LCCN-2021901137 LLNL-BOOK-818513 TID-5969