Joint designs common types

In adhesive bonding, shear is a major type of stress when one substrate is forced to move parallel and relative to the other substrate. The entire bonded area is efficiently used when joints are stressed in shear. Thus tensile-shear overlap design is a common joint design used in adhesive bonding. (See adhesives tests. Fig. A.6.)... 

It is necessary, therefore, to test an adhesive by many techniques to simulate the conditions that it may be subjected to in service. The three types of tests to be discussed are tensile, shear, and peel. These tests are the most common and result in information which is useful for reliable joint design. Response to dynamic testing such as fatigue, creep, and impact will also be introduced. 

The most common adhesive bond is the overlap or lap type. There are many variations of the overlap joint but the simplest type is the single-lap joint. This configuration has been the subject of much work (see Section III) so the geometric factors which effect joint design, such as bond area or overlap length and adherend thickness are well known. 

Whole of bond area is used to resist the applied load. This is the most common general type of adhesive joint, and the most efficient Practical joint designs must avoid the tendency of adherends to distort and peel. 

Common practice consists in investigating the influence of one experimental variable (hereafter we will refer to it as a factor while keeping other factors at a fixed value. Then, another factor is selected and modified to perform the next set of experiments, and so forth. This one-factor-at-a-time strategy has been shown to be inefficient and expensive it lacks the ability to detect the joint influence of two or more factors (z.e. it cannot address interactions) and often needs many experiments. An increase in efficiency can be achieved by studying several factors simultaneously and systematically by means of an appropriate type of experimental design. In such a way, the experiments will be able to detect the influence of each factor and also the influence of two or more factors because every observation gives information about all factors. 

Optical detectors are by far the most common in FIA, even though only a few dedicated cells have been designed as most of the cells, particularly photometric and fluorimetric, manufactured for other flow methods can be readily adapted for use in FIA. On the other hand, other optical techniques such as chemiluminescence [42] and refractometry [43], of more limited use in this methodology, have favoured the development of new types of cell suited to specific needs. At this point it is worth noting the simplicity of the joint... 

A joint is defined by its type, parameters, and auxiliary entities. The type of joint determines the degrees of freedom. Auxiliary entities are the reference points and lines needed for the definition of movements allowed by the degrees of freedom. Figure 5-20 introduces common joints from the everyday design of mechanisms by their motions, degrees of freedom, and auxiliary entities. 

FLSmidth (Pty) Ltd was awarded the contract to design, engineer, manufacture and supply, deliver to site, install and commission the mechanical portion of two Hooke s Joint type twin motor double drum BMR rock hoists and two single drum BMR single motor Personnel-Material hoists. Both rock and man/material hoists are designed to be mechanically identical with the motor identical to the recently installed In Line Rock BMR hoist at Glencore s Synclinorium shaft. Commonality of spares was a crucial feature when designing these hoists and numerous components and sub-assembhes are shared between all the hoists. 

Types of Stress. To effectively design joints for adhesive bonding, it is necessary to understand the types of stress that are common to bonded structures. Four basic loading stresses are common to adhesive joints tensile, shear, cleavage, and peel. Any combination of these stresses, illustrated in Fig. 7.13, may be encountered in an adhesive application. 

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