Load-bearing joints

Osteoarthritis is a disease of the load-bearing joints, characterised by gradual erosion of cartilage and deformation of bone. Pain is the main symptom, initially eased by rest, but later analgesics such as aspirin-like drugs are indicated. 

The development of satisfactory total replacement synovial joints is sometimes described as the major advance in orthopaedic surgery in recent times. The hip joint was the first major load bearing joint to respond to the efforts of surgeons, engineers and materials scientists in the past two decades to develop satisfactory replacements, but attention is now focussed upon the more complex knee joint. 

Sealants may be puttylike mastics, noncured tapes or cured gaskets. The widely used puttylike sealants which are emphasized in this and subsequent chapters are available as both one component and two component formulations. The term sealants is used to describe compositions used as load bearing joints and the term "caulks" is used to describe those used as nonload bearing compositions. 

This book provides a complete and clear introduction to the use of adhesives to form load-bearing joints in bridges, civil engineering and building structures. 

Structural adhesives are adhesives that are used to assemble structural bonds, that is, adhesives that are used to assemble load-bearing joints where the load may be either static or dynamic. These adhesives are differentiated form other adhesives in that they are normally the only load-bearing components of the structural assembly, and as such the demands and requirements of structural adhesives are greater than for most other adhesive types. 

EN 715 End-load-bearing joints between small diameter pressure pipes and fittings - test method for leaktightness under internal water pressure, including end thrust. 

Load-bearing joints, such as H, tapered H, intersecting Pi, T, tapered T, X, cruciform, I beams, and single- and double-blade joints... 

By definition, a structural bond involves the formation of a load-bearing joint between high-strength materials, typically metal, wood, ceramic, and certain plastics. The first step in the selection of a joining method should be a comparison of the relative merits of the available techniques.In addition to structural adhesives, these include a number of mechanical fastening methods, such as screws, bolts, nails, staples, and rivets, as well as metal fusion processes. Many of these techniques are usually associated with the joining of metal structures. 

Nevertheless, auto makers and adhesive formulators have been able to work around these difficulties and structural plastics are being used in increasing amounts. For example, the hood of the 1984 Pontiac Fiero consists of two plastic panels adhesively bonded together. The RRIM panels on the car s doors are also adhesively bonded. Ford has recently built an experimental car in which the body, chassis, and power train are made of graphite-reinforced composites. Almost the entire assembly, including primary load bearing joints, was bonded with a polyurethane structural adhesive in place of mechanical fasteners or welds. ... 

Table 1 provides the approximate load bearing capabiUties of various adhesive types. Because the load-bearing capabiUties of an adhesive are dependent upon the adherend material, the loading rate, temperature, and design of the adhesive joint, wide ranges of performance are Hsted. 

Load bearing capabiUties are dependent upon the adherend, joint design, rate of loading, and temperature. Values given represent the type of adherends normally used at room temperature. Lap shear values approximate those obtainable from an overlap of 3.2 cm. ... 

ISO 13783 1997 Plastics piping systems - Unplasticized poly(vinyl chloride) (PVC-U) end-load-bearing double-socket joints - Test method for leaktightness and strength while subjected to bending and internal pressure... 

A significant contribution of Raman spectroscopy to the analytical characterization of biomedical issues has been made in the area of biomaterials, especially in the identification of biodegradation and deterioration [1, 2]. The general impact of Raman spectroscopy on the study of biomaterials has been described by this author in three recent review articles [3-5]. In this chapter, the topic of Raman characterization of biomaterials is revisited with particular emphasis placed on those biomaterials widely employed for load-bearing surfaces in artificial joints. Important recent case studies are presented to illustrate the power of the Raman technique to answer key questions of broad medical, scientific, and technological interest. The analytical and physical science lying behind the Raman effect is shown to contribute to the accumulation of a wealth of fundamental information about the medical and technical achievements of prosthesis makers. 

Co-cured lap joints, surface roughness, stacking sequence, manufacturing pressure, tensile load bearing capacity, fatigue characteristics. 

The bond length of the specimens under cyclic tensile test was 20mm. Cyclic tensile tests were performed under the condition of stress ratio 7 = 0.1 and a loading frequency / = 5 Hz. Cyclic tensile loads applied to the co-cured single lap joint specimens were 30%, 40%, 50%, 60%, and 70% of the tensile load bearing capacity obtained from the static tensile load test. 

Fig. 5. Tensile load bearing capacities of the co-cured lap joints with respect to the surface roughness between steel and composite adherends. (a) Co-cured single lap Joint and (h) cocured double lap Joint.

Tensile load bearing capacities of the co-cured lap joints with respect to the... 

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