Rigid joints

Figure 4. Effect of 100% RH ai 21 C on the bond strength of a stainless steel joint—rigid polyurethane adhesive.

One can use another way to describe the long macromolecule. One can see that at high temperatures there is no correlation between the orientations of the different parts of the macromolecule, which are not close to each other along the chain. This means that the chain of freely-jointed rigid segments reflects the behaviour of a real macromolecule. This model carries the name of Werner Kuhn who introduced it in his pioneering works (Kuhn 1934). 

Surface deformation is another very common type of distress of jointed rigid pavements. Surface deformation is the difference in elevation across a joint or a crack resulting from vertical movements. 

Need for jigs and fixtures to keep joints rigid during welding and subsequent cooling to reduce distortion on iarge fabrications. 

Variations in flatness and squareness of abutment faces in assemblies can affect joint rigidity, corrosion resistance and sealing integrity. 

Tension leg platforms (TLP) are used mainly in deep water where rigid platforms would be both vulnerable to bending stresses and very expensive to construct. A TLP is rather like a semi-submersible rig tethered to the sea bed by jointed legs kept in tension. Tension is maintained by pulling the floating platform down into the sea below its normal displacement level. The legs are secured to a template or anchor points installed on the seabed. 

Fig. XII-15. Diagram of peel test. A and B, adhesive joint C, double Scotch adhesive tape and D, rigid support. (From Ref. 107. By permission of IBC Business Press, Ltd.)...

Rigid bones are needed for kinetic motion, support of internal organs, and muscle strength. The bones that compose the human thigh are pound for pound stronger than steel. Nature meets these needs by separating the skeleton into several bones and bone systems, creating joints where the bones intersect. 

Link-Suspended Basket Centrifuges In centrifuges with diameters larger than 762 mm (30 in), the basket, curb, curb cover, and drive form a rigid assembly flexibly suspended from three fixed posts (also known as a three-column centrifuge). The three suspension members may be either chain hnks or stiff rods in ball-and-socket joints and are spring-loaded. The suspended assembly has restrained freedom to oscillate to compensate for a normal out-of-balance condition. The drive is vertical with more efficient power transmission compared to the base-bearing type. 

Using a rear-wheel-drive vehicle as an example, a prop shaft delivers power from the transmission output, near the middle of the vehicle, to the differential that drives the wheels at the rear. If this prop shaft is designed to be stiff, which is normally the case, it could not be rigidly attached to the transmission output at one end and the differential at the other because of the differences in vertical movement between the drive wheels and the chassis. Typically, two universal joints are inserted into the drivetrain to accommodate this situation. 

It is often necessary to compute the forces in structures made up of connected rigid bodies. A free-body diagram of the entire structure is used to develop an equation or equations of equilibrium based on the body weight of the structure and the external forces. Then the structure is decomposed into its elements and equilibrium equations are written for each element, taking advantage of the fact that by Newton s third law the forces between two members at a common frictionless joint are equal and opposite. 

For purposes of this specification, stresses in the individual members of a latticed or trussed structure resulting from elastic deformation and rigidity of joints are defined as secondary stresses. These secondary stresses may be taken to be the difference between stresses from an analysis assuming fully rigid joints, with loads applied only at the joints, and stresses from a similar analysis with pinned joints. Stresses arising from eccentric joint connections, or from transverse loading of members between joints, or from applied moments, must be considered primary stresses. 

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