Search Results for clamping force

Ultrasonic metal welding is a solid-state welding process that produces coalescence through the simultaneous application of localized high-frequency vibratory energy and moderate clamping forces. This article discusses the parameters to be considered when selecting a suitable welder for ultrasonic metal welding. It details the personnel requirements, advantages, limitations, and applications, namely, wire welds, spot welds, continuous seam welds, and microelectronic welds of ultrasonic metal welding.

This article provides an overview of the relationships between torque, angle-of-turn, tension, and friction and explains how they are measured and evaluated. It focuses on the principle, test equipment, procedure, evaluation, and test report of various testing methods, namely, friction coefficient testing, torque tension testing, locknut testing, and angular ductility and rotational capacity tests. The article reviews the basic methods and fundamental principles for mechanical testing of externally and internally threaded fasteners and bolted joints. The test methods for externally threaded fasteners include product hardness, proof load, axial and wedge tension testing of full-sized products, tension testing of machined test specimens, and total extension at fracture testing. Product hardness, proof load, and cone proof-load test are the test methods for internally threaded fasteners. The article concludes with a description of torque-angle signature analysis and the specification of measurement accuracy for torque and clamp force.

Seals are mechanical components that prevent the leakage, diffusion, transfer, or mixing of different liquid, gas, solid, and multiphasic substances. This article begins by discussing the classifications of seals: static and dynamic. Static seals involve both self-energizing elastomeric materials such as O-rings, which merely react to a sealed fluid pressure, and passive materials that require clamping forces to achieve sealing, such as gaskets. The types of dynamic seals include rotary seals and reciprocating seals. The article describes the factors affecting seal wear and failure. It provides a list of some common seal wear modes and failures, namely abrasion, cavitation damage, chemical attack, compression set, corrosion, damage during abrupt decompression, dieseling damage, extrusion damage, installation damage, spiral or rolling damage, and vaporization damage. The article concludes with specific recommendations for reducting of seal friction and wear.

A fixture is a special workholding and supporting device designed and built for a particular part or shape that can be made by using standardized components, such as drill bushings, locating buttons, and clamping devices. This article provides a discussion on optimum fixture design and describes the clamping methods, namely, manual clamping, pneumatic clamping, and hydraulic clamping, and their specific principles. It presents an overview on modular fixturing for limited production. The article concludes with information on cost factors in fixturing.

The cold chamber die casting process is used with higher-melting-point alloys such as aluminum and magnesium. This article discusses the component design of the cold chamber high-pressure die casting machine. It reviews the process parameters of cold chamber die casting, incuding the shot profile, intensification phase, and component size.

This article discusses the properties of threaded fasteners made from carbon and low-alloy steels containing a maximum of 0.55% carbon. It provides guidelines for the selection of steels for bolts, studs, and nuts intended for use at temperatures between -50 and 370 deg C. The article also discusses steels rated for service above 370 deg C and describes internationally recognized grade designations. The specifications provided can be used to outline fastener requirements, control manufacturing processes, and establish functional or performance standards. The most commonly used protective metal coatings for ferrous metal fasteners; zinc, cadmium, and aluminum; are described as well.

This article focuses on the factors to be considered for selecting fasteners for joining carbon fiber composites. These considerations include corrosion compatibility, fastener materials, strength, stiffness, head configurations, importance of clamp-up, hole fit, and lightning protection.

Injection molding is a process of forcing or injecting a fluid plastic material into a closed mold. The process generally has the advantages of being more readily automated and of permitting finer part details. Injection-molding compounds are thermoplastic or thermosetting materials and their composites that are specifically formulated for the injection-molding process. This article discusses the injection molding process, which includes the two basic categories of thermoplastic and thermoset injection molding, and lists the common thermoplastic and thermoset molding compounds and applications. It also describes the operation of the different types of injection molding machines as well as mold design and process controls. The article also describes the selection of injection-moldable thermosets, and provides an overview of part performance, properties, blowing agents, and aesthetic concerns related to thermoplastic structural-foam injection molding.

This article discusses the effect of thread design, preload, tightening, and mean stress on the fatigue strength of bolt steel. It describes the factors influencing fatigue failures in cold-driven and hot-driven riveted joints. The factors affecting the fatigue resistance of bolted friction joints are also discussed. The article reviews stress concentrations in pin joints and discusses stress-intensity factors for mechanically fastened joints.

This article begins with a discussion on the advantages and limitation of ultrasonic welding (USW). It describes variations of the USW process which can produce different weld geometries. These variations are helpful in producing spot welds, line welds, continuous seam welds, ring welds, and microelectronic welds. The article provides information on the functions of USW personnel and describes the special conditions in USW which include the condition of the surface, the use of an interlayer, and the control of resonance. It concludes with a description on the weld quality, the influencing factors, surface appearance and deformation, and metallographic examination.

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.