Successful Joint Design

Bond stresses, materials, type of cyanoacrylate, surface preparation, method of application and production requirements should all be considered in relation to each other at the 

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Some researchers have also measured what they perceive to be fracture-mechanics properties under up to three modes, the first being crack-opening, and the second shear, thinking that these properties could form the basis of bonded joint design. The author has yet to see any successful joint designed using these properties and will not discuss them further. No such... 

The ultrasonic welding of ETFE can be achievedl" with a weld factor of 0.8. The success of this technique is dependent on joint design and welding parameters such as the contact time and pressure. Typical welding conditions include a contact pressure of 170 kPa and a cycle time of 2 secs. 

Proper fixturing is critical to the success of FSW and FSP. Because these processes have very high forces, the fixturing must be built to withstand the forces. Additionally, the part must be fully supported on the backside. Furthermore, the fixturing must be designed to prevent parts from moving relative to one another. These considerations are a function of the joint design. 

The finite element analysis technique has been used very successfully to confirm the regions of concentrated stress and strain. In this technique, the bonded assembly is subdivided into small elements and the forces relevant to each element are computed using basic mathematical equations. This is very useful, particularly in the understanding of complex joint designs. 

The successful and cost-effective application of adhesive bonding technology is crucially dependent on correct joint design. The adhesive joint must be adequately dimensioned for the forces to transmit. Large static loads should be avoided wherever possible - especially where the joint is exposed to higher temperatures. In such cases, joints should be optimised to provide additional support. Similar measures should be taken to counteract peeling stresses (Fig. 24). Some examples are illustrated in the chapter Technical Characteristics in Volume 1. 

Energy director joint design is not generally recommended for the more crystalline materials the scarf joint is preferred. Shear bead joints do not usually offer high strength but are satisfactory where hermeticity is required. The interference joints are successful where a slight warp-age is present which would prevent the full contact area of a scarf joint. 

Important determinants of bond quality in induction welding are the joint design and work coil design. Proper coil and joint designs are essential for good welds and determine whether or not electromagnetic welding can be used successfully. Other parameters... 

From the viewpoint of the adhesive technologist, plastics are an anomaly bonded joints can be made in which the plastic fails before the adhesive, but certain plastics are very difficult to bond. Although plastics often present difficulties in adhesive bonding (Table 4.2), all can be joined successfully with the correct choice of adhesive, joint design, and surface preparation [28] ... 

Let us suppose that the adhesive is to be used in some joint, the geometry and loading of which is quite complicated. Ultimately, the only real test of suitability is to build a representative sample of these joints for each candidate adhesive and surface treatment. This, of course, is costly and begs the question as to whether the joint design is itself satisfactory. The designer will wish to call on previous experience with adhesives, surface treatments, and joint designs so as to reach a 90% certainty of success before he builds and tests a structural prototype. If structures are expensive, it will be difficult to justify more than a very limited series of prototype tests before production ensues. Fortunately, over the last 20-30 years, a series of standard tests has been developed by means of which the mechanical properties of most adhesives can be tested. Unfortunately, the designer has to select the appropriate test(s) and to know what the results mean in terms of his particular application. 

Understanding the principles of plastics joining, the capabilities of each method and proper implementation of the appropriate joint design, can provide the designer with a clear direction at the outset and a successful an repeatable assembly result for the part. 

Various companies worked on the development of Fluid catalytic cracking units. During World War II, the government requested some of the leaders in this field to pool their knowledge so as to speed the production of aviation gasoline. The fact that so many Fluid units were constructed and put into operation in such a short time shows that this joint effort was successful. However, because of this effort, many of the basic Fluid patents were held for many years in combination with other companies, some of which also developed their own Fluid designs. 

Consequently, two semicommercial pilot plants have been operated for 1.5 years. One plant, designed and erected by Lurgi and South African Coal, Oil, and Gas Corp. (SASOL), Sasolburg, South Africa, was operated as a sidestream plant to a commercial Fischer-Tropsch synthesis plant. Synthesis gas is produced in a commercial coal pressure gasification plant which includes Rectisol gas purification and shift conversion so the overall process scheme for producing SNG from coal could be demonstrated successfully. The other plant, a joint effort of Lurgi and El Paso Natural Gas Corp., was operated at the same time at Petrochemie Schwechat, near Vienna, Austria. Since the starting material was synthesis gas produced from naphtha, different reaction conditions from those of the SASOL plant have also been operated successfully. 

The Compact Disk Digital Audio (CD-DA) was successfully introduced into the market in the early 1980s. It was designed to store at least one hour of high-quality stereo sound using digital techniques. Philips and Sony worked jointly on the specification for CD Audio, known as the Red Book. The use of compact disks was subsequently extended to the storage of computer data, with... 

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