The present work evaluates the application of artificial neural networks for pattern recognition of ultrasonic signals using pulse-echo and TOFD (Time of Flight Diffraction) techniques in weld beads. In this study pattern classifiers are implemented by artificial neural network of backpropagation type using MATLAB. The ultrasonic signals acquired from pulse-echo and TOFD were introduced, separ...

Ultrasonic spot welds have been used as a model system to investigate how to determine the mode-I cohesive parameters associated with interfacial fracture of a spot weld. Numerical analyses indicated that, while multiple combinations of the two cohesive parameters (characteristic strength, σ̂ , and toughness, I ) could result in virtually indistinguishable behaviors for individual geometries, on...

Ultrasonic testing is a very important non-destructive method for testing components for safety of nuclear power plants and other security and delicate parts in other industries. Nowadays, thanks to the development of computer technology, it is possible to simulate processes which occur during ultrasonic testing. That is why numerical simulations are becoming an integral part of non-destructive...

The effects of welding energy on the mechanical and microstructural characteristics of ultrasonic-welded pure copper plates were investigated. Complex dynamic recrystallization and grain growth occurred inside the weld zone during ultrasonic welding. At a low welding energy, a thin band of straight weld interfaces was observed and had an ultra-fine grain structure. With an increase in welding e...

The paper presentsan ultrasonic guided wave methodology for inspection of a fillet joint with a bend.Owing to the complex shape of the geometry, it is not amenable for conventional techniques. The methodology developed utilizes through-transmission ultrasonic testing. Two 90Δ angle beam (surface wave) ultrasonic transducers of central frequency 2.25 MHz, acting as a transmitter and a receiver a...

Ultrasonic testing is one of the most popular non-destructive methods to determine the quality in spot welds. The next step of this technology is to be able to determine the quality while the weld is being made, this advance can have a great impact on the quality assurance of joints in materials like aluminum, where the spot welding process is a difficult task. In our approach, a state-of-the-a...

This paper summarises fatigue tests on Y-joints to estimate the influence of a post weld treatment method called Ultrasonic Impact Treatment. With this method the fatigue resistance could be increased significantly. Furthermore, tubular joints of tripod structures for offshore wind energy converters are analysed with numerical simulations to judge these welded joints with the hot-spot-concept. ...

This paper reviews effects of amplitude and force control during the ultrasonic welding cycle of thermoplastics. In a previously published paper, the benefits of amplitude profiling were detailed as increased strength and reduced part marking. This paper reviews the mechanisms for such observations and details additional benefits, such as decreased residual stresses and increased solvent resist...

Laser welding has been applied to various industries, in particular, automotive, aerospace and microelectronics. Primary aim of joining two metals by keeping their properties unaltered, that can be only possible by controlling temperature, heating and cooling rates. However measurement of weld pool temperature during laser spot welding is a difficult task because of the short pulse duration, of...

Ultrasonic complex vibration welding of same and different metal specimens and structures of the welded area are studied using several complex vibration welding systems, scanning and transmission electron microscopes (SEM and TEM). Ultrasonic welding can weld various metal directly using vibration and static clamping pressure. The welding area is limited very narrow layer and can weld different...