Sawing, cutting, shearing

Two other variations are used to avoid the bending forces that occur with simple ASTM D 1002 specimens the laminated lap shear specimen (ASTM D 3165) shown in Fig. 20.6a and the double-lap specimen (ASTM D 3528) shown in Fig. 20.6b. These specimens minimize the joint eccentricity and provide higher strength values than does the singleoverlap specimen. For the specimen in Fig. 20.6a, the overlap joint can be made from saw cuts in the top and bottom substrates of a bonded laminate. This process negates the effects of extruded adhesive at the edges of the lap and the sheared edge of the standard type of lap shear specimen. As a result, the chances of deformation and uneven surface preparation are lessened. 

FIGURE 20.6 Modified lap shear specimens used to maintain axial loading (a) single-saw-cut specimen, (b) double-lap specimen.6... 

Ten prototype elements were tested in four-point bending tests under static and cyclic loading to determine the load-bearing behavior and capacity. The results of three representative bending tests are depicted in Fig. 11. As calculated, all sandwich panels failed by shear rupture of the core. The load level at which the shear failure occurred was significantly influenced by the quality of the adhesive bond between the notched core and concrete facings, [5]. After the tests, the joint quality of the panels was examined by saw cuts. 

Separating Tools Once layout is complete, the material must be separated. Common hand separating tools either remove chips (for example, a saw) or shear the material (for example, a pair of scissors) (see Figure 8-14). Common handsaws include the handsaw, the hacksaw, the coping saw, and the hacksaw. We can cut thick metal with a hacksaw, and we can shear thin metal with aviation... 

A foil, press, cutting saw, and shear machine is also used in the MB. This machine compresses and cuts scrap gsaerated in the disassembly op ations. Scrap that is generated during disassembly of Mark 22 assemblies is not processed through the foil, press, and shear machine. However, all the scrap that has accumulated from previous disassembly operations may eventually be processed through this madiine. 

Step 1 Cut substrate into appropriate panel size by either sawing or shearing. 

Routing Sawing Shearing Turning Fire hazard Lubricant or coolant Material and shape of cutting tool Quality suitability for ... 

Mercury binding leads to an increase of mass of the gold layer which can be detected by electro-acoustic transducers based on quartz microbalance (QMB the abbreviation QCM = quartz crystal microbalance is also widely used), surface acoustic waves (SAW)—devices [20] or microcantilevers [21,22], Adsorption of mercury vapour increases resonance frequency of shear vibrations of piezoelectric quartz crystals (Fig. 12.2). This process can be described by Sauerbrey equation [23]. For typical AT-cut quartz, this equation is... 

If highly resistant items (e.g. metal bars, rubbers or plastics) are to be included in the sample, they require preparation by a more appropriate method. Metals may be carefully cut down to <3 mm using a water-cooled saw or metal shear followed by cleaning to remove any contaminating swarf. Milling using... 

Fuel bundles have been declad by transverse sawing with a hacksaw blade operated under water to provide cooling and prevent zircaloy fires. The preferred saw consists of a hardened tool-steel cutting edge welded to a tough-steel blade [H2]. More fines are produced than in shearing. 

Trimming of plastics, if not performed correctly, can be damaging to formed parts and slow down or stop the output. Tools for trimming include shear discs, steel rule dies, and saws. The cutting action can be done with the usual punch press, as well as press brakes and other devices. Punch and... 

Yb which is much softer than the trivalent metals tends to fill the teeth of the hack saw. For this reason shearing or cutting with a sharp blade works better than sawing. A carborundum wheel also works better than a saw, but the SiC particles from the wheel sometimes become imbedded in the surface of the metal. The saw blades used to cut La, Ce, Pr and Nd frequently become filled with metal. The metal caught in the saw blades oxidizes in a few days and the blades can be reused after cleaning off the oxide powder. 

Another hazard is sharp objects and equipment. Examples are burrs and sharp edges on sheared sheet metal or metal objects. Another example is use of sharp knives and cutting tools. Other examples are axes and portable saws, such as chainsaws. Protective clothing, such as gloves, chaps and other clothing must be tough and resist cuts and tears. 

The angle of internal friction can be measured directly by the "grooved plate" method. The base of the Jenike shear cell is replaced by a metal plate in which a number of saw-toothed grooves are cut (Figure 2.15). These... 

Quartz is a well-known piezoelectric material. a-Quartz belongs to the triclinic crystal system with point group 32 and has a phase transition at 537°C to its P-form, which is not piezoelectric. Quartz has a cut with a zero temperature coefficient. For instance, quartz oscillators, operated in the thickness shear mode of the AT-cut, are used extensively for clock sources in computers, frequency stabilized ones in TVs and VCRs. On the other hand, an ST-cut quartz substrate with X-propagation has a zero temperature coefficient for surface acoustic wave and so is used for SAW devices with high-stabilized frequencies. The another distinguished characteristic of quartz is an extremely high mechanical quality factor Qm >10. ... 

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