Modulus of elasticity flexural

Table 10-56 gives values for the modulus of elasticity for nonmetals however, no specific stress-limiting criteria or methods of stress analysis are presented. Stress-strain behavior of most nonmetals differs considerably from that of metals and is less well-defined for mathematic analysis. The piping system should be designed and laid out so that flexural stresses resulting from displacement due to expansion, contraction, and other movement are minimized. This concept requires special attention to supports, terminals, and other restraints. 

Such degradation of the surface causes little effect on either flexural strength or flexural modulus of elasticity but the influence on the impact properties is more profound. In such instances the minute cracks form centres for crack initiation and samples struck on the face of samples opposite to the exposed surface show brittle behaviour. For example, a moulded disc which will withstand an impact of 12 ftlbf without fracture before weathering will still withstand this impact if struck on the exposed side but may resist impacts of only 0.75 ftlbf when struck on the unexposed face. 

Plastic whose apparent modulus of elasticity is not greater than 10,000 psi at room temperature in accordance with the Standard Method of Test for Stiffness in Flexure of Plastics (ASTM Designation D747). 

Table 2-4 Examples of flexural modulus of elasticity for polypropylene compounds...

The stress-strain behavior of plastics in flexure generally follows from the behavior observed in tension and compression for either unreinforced or reinforced plastics. The flexural modulus of elasticity is nominally the average between the tension and compression moduli. The flexural yield point is generally that which is observed in tension, but this is not easily discerned, because the strain gradient in the flexural RP sample essentially eliminates any abrupt change in the flexural stress-strain relationship when the extreme fibers start to yield. 

There are different techniques that have been used for over a century to increase the modulus of elasticity of plastics. Orientation or the use of fillers and/or reinforcements such as RPs can modify the plastic. There is also the popular and extensively used approach of using geometrical design shapes that makes the best use of materials to improve stiffness even though it has a low modulus. Structural shapes that are applicable to all materials include shells, sandwich structures, and folded plate structures (Fig. 3-8). These widely used shapes employed include other shapes such as dimple sheet surfaces. They improve the flexural stiffness in one or more directions. 

Flexural strength (c direction), MPa 80-170 Tensile strength (ab direction), MPa 110 Young s modulus of elasticity, GPa 28-31... 

E is still the modulus of elasticity. The E is assumed to be independent of force, rate of rupture, and so on. It has been pointed out recently99 that the wedge, unless it advances extremely slowly, is likely to cause vibrations (flexure waves) in the specimen which would necessitate an alteration of Eq. (52). 

The data available on the effect of accelerators on the flexural and tensile strengths and the modulus of elasticity are limited [22, 30, 31] and are relevant only to calcium chloride and triethanolamine. The data generally point to either no effect or a slight reduction in all three properties. Also, in view of the increase in compressive strength, it is reasonable to assume that for a given compressive strength, the presence of calcium chloride or triethanolamine will reduce the flexural and tensile strengths and the modulus of elasticity. 

Fiber type 90 flexural strength (MPa) 90 flexural strain (%) Tangent modulus of elasticity (GPa)... 

Mixture series Batch no. W/C + S S/C + S Density at 1 day (kg ComfwessiVe strength (MPa) Flexure strength[ (MPa) Modulus of Elasticity (CPa) Chloride-ion penetration (Q... 

Compressive strength, at 25°C, MPaa Modulus of elasticity, at 25°C, GPab In tension In flexure In compression Izod impact, at 25°C, J/mc Notched Unnotched... 

C-580 Flexural strength and modulus of elasticity on chemical-resistant mortars, grouts and monolithic surfacing. 

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