Knowledge: Torque & tension

Testing underpins the fastener supply chain, from the fastener manufacturer’s basic fastener product performance and specification tests to the end-user Design Engineer’s bolted joint test rig and product testing. But testing in isolation has little value for fastener manufacturers, distributors and downstream original equipment manufacturers (OEMs). Design Engineers are increasingly integrating physical testing with software-based analysis to improve product safety and quality.

Vibrationmaster is engaged in commercializing a number of product lines based on their proprietary, patented technology, enabling the generation of vibration profiles with the specific advantage of continuously and independently controlling frequency and amplitude.

Abstract. Vibration can be desirable, such as when it is used to make music. More often, however, vibration is undesirable. It can introduce stress into mechanical systems and create fatigue that decreases service life. It can also loosen fasteners. This article discusses the root causes of the self-loosening of fasteners, then two practical examples illustrate the benefits and possible applications of vibration testing of fasteners, according to either standardised testing protocols or customised testing strategies simulating real-life conditions of the assembled parts. The requirements and protocols of the international standard ISO 16130, the USA national aerospace standard NASM 1312-7, the German national standard DIN 25201-4 B and its predecessor DIN 65151 are compared, with insights on their most suitable applications. Finally, the article describes a lean methodology to design a meaningful testing protocol.

Fasteners and bolted joints quite literally hold automotive designs, assemblies and the resulting completed vehicle together. So, a complete understanding of how they perform is essential to drive innovation, improve quality and safety and introduce production efficiencies in the automotive sector. Each of these aspects contributes to the competitive advantage of automotive original equipment manufacturers (OEMs). Fastener manufacturers who understand how their products can contribute to creating competitive advantage and can develop new fasteners to meet car makers’ needs can better serve their automotive OEM customers. Vibrationmaster’s Morten Schiff and REC solutions in fastening technology’s Bernhard Reck explain how automotive OEMs apply static and dynamic fastener and bolted joint testing methodologies to drive product, quality, safety and process improvements.