A Synopsis and Copy of Published Papers from a NAFEMS Seminar held in April 2010, Wiesbaden Germany

Joints are an integral part of products in all sectors of industry, Civil and Offshore, Power and Pressure, Aerospace, Land Transport, Consumer Goods and Biomechanical applications. Joints are important not only with respect to structural integrity and performance of the products themselves but in the jigs, fixtures and test hardware used throughout the product manufacture and qualification process.

Components are assembled together to maintain structural integrity and performance using a variety of methods, either temporary mechanically fastened allowing for repeated disassembly and reassembly necessary for maintenance activities or permanent attachment.

Mechanically fastened joints may be temporary such as: bolts into nuts, anchor nuts or tapped holes, or permanent such riveted joints. Permanent joints also include for example, bonded, single lap, double lap, welded, fillet welds, spot welds, seam welds and soldered or brazed.

To maintain performance the joints need to survive all the loading environments experienced during the manufacture, assembly and testing and to deliver the required product performance throughout the in service life. These can be steady state or cyclic from vibration, shock and thermal environments or combinations of such loads at various points in the products life cycle.

Companies in the various industry sectors will have their own internal processes and methods for assessing structural integrity of the joints used with respect to their particular product or will make use of data from engineering bodies or standard engineering texts such as those listed below for example:

• Engineering Science Data Unit, ESDU, who provide data items on various engineering analysis methods and materials.
• Mechanical Engineering Design by J.E. Shigley, C.R. Mischke and R.G. Budynas.
• ECSS-E-HB-32-23A Space Engineering, Threaded Fasteners ESA-ESTEC.
• VDI 2230 Part 1Systematic Calculation of High Duty Bolted Joints - Joints with One Cylindrical Bolt
• Handbook of Bolts and Bolted Joints by J. H Bickford and S. Nassar.

Product structural integrity is now routinely assessed using simulation techniques. Therefore it is necessary to represent the wide variety of joints used in product assemblies with an idealisation at system level to represent the stiffness characteristics and to recover loads for application to more detail models to assess the integrity of the joint itself.

The availability of sources of information in the public domain on idealisation of joints in simulation of the performance of bolted, riveted, welded, brazed and soldered joints is not well defined.

This document provides a synopsis of a NAFEMS seminar on Idealisation of Joints held in Wiesbaden in April 2010 including a summary of the industry sectors that presented information, the scope of information presented and copies of papers presented.

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