Understanding the Theory and Use of Resistive Welding Technology for Fiber-Reinforced Thermoplastic Composite Structures in Automotive Applications

Transportation accounts for 14% of global greenhouse gas emissions. With a projected rise in GDP for more than half of the global population, the demand for transportation is only going to increase sharply. It is essential to reduce the overall weight of the automobile and ensure that its constituent materials are being reused with the minimal energy consumption during treatment and conversion. This is especially critical for the heaviest components in an automobile – its structure and closures. In this regard, carbon fiber reinforced composites have high light-weighting potential for automotive structures. However, most OEMs use thermoset polymers as matrix material, which are not recyclable. This has led to a great push towards the use of thermoplastics as matrix material in the future. A key issue associated with this possibility is the need for an optimal joining mechanism – since while structural adhesives are the most common joining mechanism used at present, most of these adhesives are thermoset polymers themselves that are also expensive and have longer curing time. Additionally, when used with thermoplastic matrix materials, these adhesives bring forth the problem of compatibility. The ability to be joined in fast, strong and repeatable methods is crucial for automotive structures, given that a typical body structure has between 150-400 individual parts, and their timely and strong joining is essential to ensure their applicability for mass production. In this context, the ability to be fusion bonded (or welded) is one of the key advantages of FRTPCs over thermoset composites. Welding thermoplastic reinforced composites can be segregated into three major categories: resistive implant welding (RIW), vibration welding, and electromagnetic welding. Resistive implant welding is an attractive technology due to faster cycle times, lower cost, higher design freedom, and ease of automation. Most research till date primarily focuses on processing and optimizing RIW joints for FRTPCs with high-performance polymer matrix materials that are typically used in aerospace. This dissertation primarily focuses on understanding the processability and optimizing RIW joint for FRTPC materials with engineering-grade polymers. Moreover, research to date also predominantly uses only lap shear strength to characterize these joints. However, this is not enough to adequately understand the mechanical behavior of welded joints. In this dissertation, both lap shear and peel strength were experimentally evaluated, and finite element models were created to simulate these joints under large non-linear loads such as crash tests. This exercise provided in-depth insights into effects on the component-level performance of resistive implant welded structures and their behaviors in large deformation load cases such as crash tests

Flexible Automation and Intelligent Manufacturing: The Human-Data-Technology Nexus

This is an open access book. It gathers the first volume of the proceedings of the 31st edition of the International Conference on Flexible Automation and Intelligent Manufacturing, FAIM 2022, held on June 19 – 23, 2022, in Detroit, Michigan, USA. Covering four thematic areas including Manufacturing Processes, Machine Tools, Manufacturing Systems, and Enabling Technologies, it reports on advanced manufacturing processes, and innovative materials for 3D printing, applications of machine learning, artificial intelligence and mixed reality in various production sectors, as well as important issues in human-robot collaboration, including methods for improving safety. Contributions also cover strategies to improve quality control, supply chain management and training in the manufacturing industry, and methods supporting circular supply chain and sustainable manufacturing. All in all, this book provides academicians, engineers and professionals with extensive information on both scientific and industrial advances in the converging fields of manufacturing, production, and automation

On Sensor-Controlled Robotized One-off Manufacturing

A semi-automatic task oriented system structure has been developed and tested on an arc welding application. In normal industrial robot programming, the path is created and the process is based upon the decided path. Here a process-oriented method is proposed instead. It is natural to focus on the process, since the path is in reality a result of process needs. Another benefit of choosing process focus, is that it automatically leads us into task oriented thoughts, which in turn can be split in sub-tasks, one for each part of the process with similar process-characteristics. By carefully choosing and encapsulating the information needed to execute a sub-task, this component can be re-used whenever the actual subtask occurs. By using virtual sensors and generic interfaces to robots and sensors, applications built upon the system design do not change between simulation and actual shop floor runs. The system allows a mix of real- and simulated components during simulation and run-time

Recent Advancements in Augmented Reality for Robotic Applications: A Survey

Robots are expanding from industrial applications to daily life, in areas such as medical robotics, rehabilitative robotics, social robotics, and mobile/aerial robotics systems. In recent years, augmented reality (AR) has been integrated into many robotic applications, including medical, industrial, human–robot interactions, and collaboration scenarios. In this work, AR for both medical and industrial robot applications is reviewed and summarized. For medical robot applications, we investigated the integration of AR in (1) preoperative and surgical task planning; (2) image-guided robotic surgery; (3) surgical training and simulation; and (4) telesurgery. AR for industrial scenarios is reviewed in (1) human–robot interactions and collaborations; (2) path planning and task allocation; (3) training and simulation; and (4) teleoperation control/assistance. In addition, the limitations and challenges are discussed. Overall, this article serves as a valuable resource for working in the field of AR and robotic research, offering insights into the recent state of the art and prospects for improvement

High-performance shape memory composites with intrinsic heating capabilities

Shape morphing structures have played a significant role within the field of aerospace for more than a century. While the shape morphing aerostructures of the past and present have depended on hinges and motors to achieve morphing, their future is expected to rely on smart materials and structures that have intrinsic shape morphing capabilities. One such smart material, that has previously been developed at Imperial College London, is the carbon fibre reinforced epoxy polymer (CFRP) composite with thermoplastic (TP) interleaves. These interleaved composites exhibit controllable stiffness (CS) and shape memory (SM) capabilities under suitable thermal conditions. While these interleaved composites showed excellent shape morphing capabilities, they had several drawbacks. These composites showed poor flexural modulus and through-thickness shear strength compared to the epoxy-based non-interleaved CFRP. These composites also used an oven to achieve the high temperatures required to exhibit the CS and SM capabilities. This thesis describes studies conducted to mitigate these drawbacks. In the first study described in this thesis, the source of the premature through-thickness shear failure in TP interleaved CFRP composites was discovered to be the low shear strength of the polystyrene (PS) interleaves used in previous works. It was then demonstrated that replacing PS with Poly(styrene-co-acrylonitrile) (SAN) could improve the through-thickness shear strength of the interleaved composites to be almost as high as that of pristine CFRP. Furthermore, the SAN-interleaved CFRP laminates also exhibited excellent CS and SM capabilities. In the next study described in this thesis, it was demonstrated that the flexural modulus of TP interleaved CFRP composites can be substantially improved by two different methods- (i) reducing the thickness of the TP interleaves, and (ii) introducing reinforcements within the TP interleaves. The following study describes how intrinsic heating capability was achieved in TP interleaved CFRP composites, through resistive heating of heater elements such as stainless steel (SS) meshes and woven carbon fabric (WCF) embedded within the layup of the composite. This intrinsic heating strategy was used to supply the temperature necessary for the corresponding composites to exhibit CS and SM capabilities. As a result, these intrinsically heated TP interleaved CFRP composites exhibited successful out-of-oven morphing capabilities. In the final study described in this thesis, composite structures that were initially flat in their as-cured state, but were capable of deployment into planar and curved meshes were designed. Finite element numerical models were used to predict the deployment capabilities of these composite structures. Finally, the deployable composite mesh structures were manufactured and characterised.Open Acces

Flexible Automation and Intelligent Manufacturing: The Human-Data-Technology Nexus

This is an open access book. It gathers the first volume of the proceedings of the 31st edition of the International Conference on Flexible Automation and Intelligent Manufacturing, FAIM 2022, held on June 19 – 23, 2022, in Detroit, Michigan, USA. Covering four thematic areas including Manufacturing Processes, Machine Tools, Manufacturing Systems, and Enabling Technologies, it reports on advanced manufacturing processes, and innovative materials for 3D printing, applications of machine learning, artificial intelligence and mixed reality in various production sectors, as well as important issues in human-robot collaboration, including methods for improving safety. Contributions also cover strategies to improve quality control, supply chain management and training in the manufacturing industry, and methods supporting circular supply chain and sustainable manufacturing. All in all, this book provides academicians, engineers and professionals with extensive information on both scientific and industrial advances in the converging fields of manufacturing, production, and automation

Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

Small business innovation research. Abstracts of completed 1987 phase 1 projects

Non-proprietary summaries of Phase 1 Small Business Innovation Research (SBIR) projects supported by NASA in the 1987 program year are given. Work in the areas of aeronautical propulsion, aerodynamics, acoustics, aircraft systems, materials and structures, teleoperators and robotics, computer sciences, information systems, spacecraft systems, spacecraft power supplies, spacecraft propulsion, bioastronautics, satellite communication, and space processing are covered