Automated object detection of mechanical fasteners using faster region based convolutional neural networks

Mechanical fasteners are widely used in manufacturing of hardware and mechanical components such as automobiles, turbine & power generation and industries. Object detection method play a vital role to make a smart system for the society. Internet of things (IoT) leads to automation based on sensors and actuators not enough to build the systems due to limitations of sensors. Computer vision is the one which makes IoT too much smarter using deep learning techniques. Object detection is used to detect, recognize and localize the object in an image or a real time video. In industry revolution, robot arm is used to fit the fasteners to the automobile components. This system will helps the robot to detect the object of fasteners such as screw and nails accordingly to fit to the vehicle moved in the assembly line. Faster R-CNN deep learning algorithm is used to train the custom dataset and object detection is used to detect the fasteners. Region based convolutional neural networks (Faster R-CNN) uses a region proposed network (RPN) network to train the model efficiently and also with the help of Region of Interest able to localize the screw and nails objects with a mean average precision of 0.72 percent leads to accuracy of 95 percent object detection

BOND QUALITY EVALUATION USING ADHESIVE DOPED WITH MAGNETO-ELECTRIC NANOPARTICLES

Adhesive bonding for composite structures offers multiple advantages over mechanical fasteners. Although the use of adhesive bonding has increased in the aerospace industry, it has still not replaced mechanical fasteners due to it being harder to inspect for damage after being manufactured/assembled, causing unreliability. Therefore, intensive quality control is needed while manufacturing to avoid weak bonds or any type of imperfection at the adhesive-adherend interface. To ensure the reliability of an adhesive bond, this project focuses on the advancement of a non-invasive field tool for adhesive quality evaluation. The tool developed is based on a B-H looper system, which can approximate the quality of an epoxy-based adhesive containing magneto-electric nanoparticles (MENs) by detecting changes in electric fields at the molecular level. Epoxy based adhesive samples containing 5 vol. % of MENs were manufactured and then scanned using the B-H looper system to correlate their magnetic signature as a function of curing time. It was determined that the magnetic signal converged between curing hours 10 and 12, indicating proper curing. Plain adhesive dogbone samples were used to determine the maximum tensile stress of the adhesive as a function of curing time, which also started converging at around the same curing hours until reaching ~41 MPa. Additionally, the evolution of the glass transition temperature of the adhesive was evaluated during the first curing hours. Convergence began at a curing time of 10 hours until reaching ~137 ⁰ C for fully cured samples. B-H looper magnetic signatures, tensile stresses testing, and glass transition temperatures were all correlated indicating a fully cured adhesive sample between 10 and 12 curing hours. These studies demonstrate the capabilities of the B-H looper system as a non-invasive inspection tool for adhesive quality.

Failures of Mechanical Fasteners

This article first provides an overview of the types of mechanical fasteners. This is followed by sections providing information on fastener quality and counterfeit fasteners, as well as fastener loads. Then, the article discusses common causes of fastener failures, namely environmental effects, manufacturing discrepancies, improper use, or incorrect installation. Next, it describes fastener failure origins and fretting. Types of corrosion in threaded fasteners and their preventive measures are then covered. The performance of fasteners at elevated temperatures is addressed. Further, the article discusses the types of rivet, blind fastener, and pin fastener failures. Finally, it provides information on the mechanism of fastener failures in composites.

Conventional Selection of Mechanical Fasteners for Flat Belts

Due to the variety of materials used for flat belts of belt conveyors and the further development of material engineering in relation to these belts, the methods of their connection become an increasingly problematic issue. The belts can be connected mainly in three ways: vulcanized (weldable or heat-weldable), glued or mechanically. The latter method is one of the simplest and most universal in terms of the material variety of belts; however, there are many design variations of mechanical fasteners, and each of them has a certain advantage in a narrow group of properties, e.g., the thickness spectrum of a conveyor belt, the minimum diameter of a drive roller or the range of transferable longitudinal loads. The objective of this paper is to analyze the design solutions of commercial mechanical fasteners used mainly for flat rubber-fabric, composite or plastic belts. To fulfill this goal, a preliminary analysis of the stress distribution for an exemplary solid mechanical fastener was carried out in two cases: during ramp-up and during circulating around the roll, followed by a detailed review of commercial solutions available on the market. In addition to determining the current state of knowledge and technology and determining the state of ignorance, special algorithm and design maps have been created, thanks to which the process of selecting the right mechanical fastening will be easier. The overview includes several tables with detailed information on individual connection properties. Additionally, several design aspects were derived, within which individual mechanical connections may differ. This is to enable the generation of customized solutions in the future by proposing an appropriate mathematical model, on the basis of which it will be possible to generate optimal design properties for a given application.