Steel modulus

The actual experimental moduli of the polymer materials are usually about only % of their theoretical values [1], while the calculated theoretical moduli of many polymer materials are comparable to that of metal or fiber reinforced composites, for instance, the crystalline polyethylene (PE) and polyvinyl alcohol have their calculated Young s moduli in the range of 200-300 GPa, surpassing the normal steel modulus of 200 GPa. This has been attributed to the limitations of the folded-chain structures, the disordered alignment of molecular chains, and other defects existing in crystalline polymers under normal processing conditions. 

The modulus of elasticity (MOE) is related to the strength and can be used as a nondestmctive quaUty control test on high cost special refractory shapes such as sHde gate valves employed in the pouring of steel (qv). The sHde gate type must be selected to ensure chemical compatibiUty and it must be used in a way to reduce thermal shock. The performance of a properly selected and used sHde gate is direcdy related to its strength and therefore predicted by its MOE. 

Strength and modulus normali2ed to linear density (Tex = (g-wt)/km), an appropriate basis for materials of similar density however, this breaks down for dense materials (eg, steel) because the basis for tire use is better described by properties per unit cross section (MPa) rather than weight. 

Cord materials such as nylon, polyester, and steel wire conventionally used in tires are twisted and therefore exhibit a nonlinear stress—strain relationship. The cord is twisted to provide reduced bending stiffness and achieve high fatigue performance for cord—mbber composite stmcture. The detrimental effect of cord twist is reduced tensile strength. Analytical studies on the deformation of twisted cords and steel wire cables are available (22,56—59). The tensile modulus E of the twisted cord having diameter D and pitchp is expressed as follows (60) ... 

In energy extraction, titanium alloys are being used in deep-water hydrocarbon and geothermal weUs for risers. Corrosion resistance, high strength, low modulus (flexible), and low density can result in risers one-fourth the weight and three times the flexibiHty of steel. 

Composite Modulus of Elasticity. The modulus of elasticity of the enamel glass—steel composite system has been shown to lie between the modulus of the glass and that of the metal (29). The composite modulus can be calculated by... 

Example 10 Response to Instantaneous Valve Closing Compute the wave speed and maximum pressure rise for instantaneous valve closing, with an initial velocity of 2,0 m/s, in a 4-in Schedule 40 steel pipe with elastic modulus 207 X 10 Pa, Repeat for a plastic pipe of the same dimensions, with E = 1.4 X 10 Pa. The liquid is water with P = 2.2 X 10 Pa and p = 1,000 kg/m. For the steel pipe, D = 102,3 mm, b = 6,02 mm, and the wave speed is... 

A typical screwdriver has a shaft and blade made of a high-carbon steel, a metal. Steel is chosen because its modulus is high. The modulus measures the resistance of the material to elastic deflection or bending. If you made the shaft out of a polymer like polyethylene instead, it would twist far too much. A high modulus is one criterion in... 

Materials respond to stress by straining. Under a given stress, a stiff material (like steel) strains only slightly a floppy or compliant material (like polyethylene) strains much more. The modulus of the material describes this property, but before we can measure it, or even define it, we must define strain properly. 

The maximum eoeffieient of variation for the Modulus of Elastieity, E, for earbon steel was given in Table 4.5 as Cy = 0.03. Typieally, E = 208 GPa and therefore we ean infer that E is represented by a Normal distribution with parameters ... 

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