Cohesive mixed-mode damage model applied to the simulation of the mechanical behaviour of a repaired sandwich beam

The behaviour of a repaired sandwich beam loaded under four point bending is simulated using theABAQUS® software. Both overlap and scarf repair, suitable for sandwich structures, were simulatedconsidering two dimensional nonlinear material and geometrical analysis. Special developed interfacefinite elements including a trapezoidal cohesive mixed-mode damage model appropriate for ductileadhesives were used in order to simulate the adhesive layer. The proposed model is intended to replacethe continuum finite elements traditionally used to simulate the adhesive layer, thus reducing thecomputational effort necessary to obtain results. Double Cantilever Beam (DCB) and End NotchedFlexure (ENF) tests were used to obtain the cohesive laws of the adhesive in pure modes I and II,respectively. The fracture energies (JIc and JIIc) are obtained using a new data reduction scheme based oncrack equivalent concept allowing overcoming crack monitoring difficulties during propagation in thesefracture characterization tests. The remaining cohesive parameters (1,I, 1,II, 2,I, 2,II)are obtained usingan inverse method, which is based on the fitting of the numerical and experimental P- curves by a finetuning process. This procedure allows fixing the referred cohesive parameters to be used in the stressanalyses and strength predictions of repaired sandwiches. The numerical model allowed the simulation ofdamage initiation and growth. Geometric changes, such as patch overlap length and scarf angle wereconsidered in the analysis in order to assess their influence on the repair efficiency. Conclusions weredrawn about design guidelines of sandwich composite material repair

Taper angle optimization of scarf repairs in carbon-epoxy laminates

The increasing use of Carbon-Fibre Reinforced Plastic (CFRP) laminates in high responsibility applications introduces an issue regarding their handling after damage. The availability of efficient repair methods is essential to restore the strength of the structure. The availability of accurate predictive tools for the repairs behaviour is also essential for the reduction of costs and time associated to extensive tests. This work reports on a numerical study of the tensile behaviour of three-dimensional (3D) adhesively-bonded scarf repairs in CFRP structures, using a ductile adhesive. The Finite Element (FE) analysis was performed in ABAQUS® and Cohesive Zone Models (CZM’s) was used for the simulation of damage in the adhesive layer. A parametric study was performed on two geometric parameters. The use of overlaminating plies covering the repaired region at the outer or both repair surfaces was also tested as an attempt to increase the repairs efficiency. The results allowed the proposal of design principles for repairing CFRP structures

Industrial Process Improvement by Automation and Robotics

Automation and robotics have revolutionized industrial processes, making them more efficient, precise, and flexible [...

Advances in Numerical Modeling of Adhesive Joints

VI, 151p. 64 illus.online resource

Advances in Numerical Modeling of Adhesive Joints

This book deals with the most recent numerical modeling of adhesive joints. Advances in damage mechanics and extended finite element method are described in the context of the Finite Element method with examples of application. The book also introduces the classical continuum mechanics and fracture mechanics approach and discusses the boundary element method and the finite difference method with indication of the cases they are most adapted to. At the moment there a no numerical technique that can solve any problem and the analyst needs to be aware of the limitations involved in each case

Volume 1: Modern Manufacturing

This volume of LectureNotes in Mechanical Engineering (LNME) is one of two volumes including papers selected from the 32nd International Conference on Flexible Automation and Intelligent Manufacturing (FAIM 2023), held in Porto, Portugal, from June 18 to 22, 2023. The FAIM 2023 conference was organized by the School of Engineering, Polytechnic of Porto, located in Porto, Portugal. Flexible Automation and Intelligent Manufacturing (FAIM) is a renowned international forum for academia and industry to disseminate novel research, theories, and practices relevant to automation and manufacturing. For over 30 years, the FAIM conference has provided a strong and continuous presence in the international manufacturing scene, addressing both technology and management aspects via scientific conference sessions, workshops, tutorials, and industry tours. Since 1991, FAIM has been hosted in prestigious universities on both sides of the Atlantic and, in recent years, in Asia. The conference attracts hundreds of global leaders in automation and manufacturing research whoattend program sessions where rigorously peer-reviewed papers are presented during themultiple-day conference. The conference links researchers and industry practitioners in a continuous effort to bridge the gap between research and implementation. FAIM 2023 received more than 400 contributions from over 40 countries and over 220 institutions around the world. After a two-stage double-blind review, the technical program committee accepted 263 papers. From these, 242 papers have been included in two LNME volumes, and 21 extended papers are published as fast-track articles in Robotics and Computer-Integrated Manufacturing and The International Journal of Advanced Manufacturing Technology. A selection of these LNME articles will be invited to submit substantially extended versions to special issues in ten international indexed journals, such as the International Journal of Computer Integrated Manufacturing, Journal of Mechanical Engineering Science, Journal of Testing and Evaluation, Sustainability journal, Machines journal, Metals journal, Actuators journal, Systems journal, FME Transactions journal, and Technological Sustainability journal. We are grateful to the authors for their contributions and would like to acknowledge the FAIM steering committee, advisory board committee, honorary chairs, the scientific committee members, and manuscript reviewers for their significant efforts, continuous support, sharing their expertise, and conducting manuscript reviews.Manuscript reviewers came from various locations around the world, performing 1339 reviews in total. With such effort and toughness, the high standards of the papers included in the FAIM program have been kept.info:eu-repo/semantics/publishedVersio

Increasing the Environmental Sustainability of an Over-Injection Line for the Automotive Component Industry

Thermoplastic injection is currently employed in different industrial fields. This process has significantly evolved over the years, and injection machine manufacturers are continuously forced to innovate, to improve the energetic efficiency, aiming to reduce costs, improve competitiveness, and promote environmental sustainability. This work focuses on the development of a novel, profitable, and environmentally friendly plastic over-injection equipment of small metallic parts for the automotive industry, to be applied in a bowden cable production line, to cover the zamak terminations with plastic, or produce terminations entirely made of plastic. The work is based on an over-sized existing solution. The operating parameters required for the work are quantified, and all machine parts are designed separately to achieve the required functionality. Known approaches are finally used to perform the cost analysis, calculate the return on investment (ROI), and energetic efficiency, to substantiate the replacement of the current solution. The new equipment was able to increase the energetic efficiency of the current assembly line while keeping the required injection rates. An efficient and sustainable solution was presented, with a ROI of 1.2 years over the current solution. The proposed design is also applicable to different automated production lines that require this technology. Nowadays, this concept can be extended to all fields of industry that employ injection molding in their processes, enabling to integrate new manufacturing systems, and increasing energetic efficiency while reducing production costs

Increasing the Environmental Sustainability of an Over-Injection Line for the Automotive Component Industry

Thermoplastic injection is currently employed in different industrial fields. This process has significantly evolved over the years, and injection machine manufacturers are continuously forced to innovate, to improve the energetic efficiency, aiming to reduce costs, improve competitiveness, and promote environmental sustainability. This work focuses on the development of a novel, profitable, and environmentally friendly plastic over-injection equipment of small metallic parts for the automotive industry, to be applied in a bowden cable production line, to cover the zamak terminations with plastic, or produce terminations entirely made of plastic. The work is based on an over-sized existing solution. The operating parameters required for the work are quantified, and all machine parts are designed separately to achieve the required functionality. Known approaches are finally used to perform the cost analysis, calculate the return on investment (ROI), and energetic efficiency, to substantiate the replacement of the current solution. The new equipment was able to increase the energetic efficiency of the current assembly line while keeping the required injection rates. An efficient and sustainable solution was presented, with a ROI of 1.2 years over the current solution. The proposed design is also applicable to different automated production lines that require this technology. Nowadays, this concept can be extended to all fields of industry that employ injection molding in their processes, enabling to integrate new manufacturing systems, and increasing energetic efficiency while reducing production costs

A Novel Fully Automatic Concept to Produce First Subset of Bowden Cables, Improving Productivity, Flexibility, and Safety

With a view to maintaining the competitiveness required by the market, the automotive industry strongly encourages its suppliers to develop new production methods and technologies capable of reducing the costs of produced products, ensuring the necessary quality, and increasing flexibility, with a view to responding more easily to the customization of the products that the market increasingly demands. The main goal of this work was to increase the flexibility and productivity of equipment capable of producing the first subset that constitutes the product commonly known as the Bowden cable. To this end, the design science research methodology was used, which was understood as the most effective in describing scientific work related to the improvement of existing systems. Bowden cables are cables that activate various devices in the car, such as opening doors, moving window glasses, and adjusting some car seats, among others. The work consisted of integrating several operations usually carried out for the manufacture of the referred subset, reducing logistics operations and manual work, increasing operator safety, and increasing the production rate and flexibility of the equipment, by reducing the setup time. For this purpose, new mechanical concepts were developed, and automation was applied, which resulted in a completely new concept, able to fulfill all the objectives initially set. It should be noted here that the new equipment allowed a production rate of 1140 p/h, when the initial objective was 1100 p/h; it requires an investment of only around EUR 55,000 (easy return on investment), occupies only 11.6 m2, and has reinforced safety systems to avoid workers’ injuries, an aspect that is very important in this type of equipment, where operators deal with cutting systems and high temperatures. The dissemination of this concept could help other researchers to easily find solutions to certain problems that they face in the development of modern equipment. The main contributions of this paper are the novel concepts created to overcome some process difficulties, which can be used for a wide range of other processing situations with similar difficulties. The solutions proposed allow a decrease in the cycle time, present high flexibility, save workshop space, and are affordable in terms of global cost