Maximum tensile strength

A unidirectional fibre composite consists of 60% by volume of continuous type-1 carbon fibres in a matrix of epoxy. Find the maximum tensile strength of the composite. You may assume that the matrix yields in tension at a stress of 40 MPa. 

The tensile strength of NR compounds in the presence of cross-link promoters such as dichlorobenzene is increased as compared to the sulfur-accelerator and peroxide-curing systems. The retention of the maximum tensile strength at elevated temperamres is greater for radiation cured than for chemically vulcanized NR [326,327]. Also reported are a higher abrasion resistance [328] and a lower flex life in the case of radiation-cured system. Effect of phenoxy ethyl acrylate (PEA)... 

Immediately below the nozzle a tube is formed from a strip of paper which is bent round in a forming die. The paper tube thus formed and containing relatively loose PETN passes through a second die, at which stage it is also spun with textile, often in this case jute to give maximum tensile strength. This second die is smaller than the first and therefore exerts a consolidating... 

The maximum tensile strength of the pseudo-IPNs appeared at about the 80 20 ratio of PU/VMCC for both pseudo-IPNs with and without opposite charge groups. Presumably the maximum entangle-ment between the VMCC chains and the PU network also occurred at this composition ( Figure 1). ... 

Clearly, large doses are required for a full cure. The dose levels for attaining a maximum tensile strength are within 20 to 50 Mrad (200 to 500 kGy). 

The retention of the maximum tensile strength at elevated temperatures is greater for radiation cured than for chemically cured natural rubber. The physical properties after high-temperature aging are not improved, however. Lower flex life and higher abrasion resistance of radiation cross-linked NR were reported. Other properties, such as permanent set, hardness, and resilience, were found to be nearly equal. 

The prevulcanization of natural rubber in latex form has also been a subject of much investigation. The cross-linking mechanism is not yet fully understood, but the water apparently plays a major role in it. Irradiation results in the cross-linking of the rubber molecules and in coarsening of the latex particles. A process of cross-linking of natural rubber latex has been developed to the point that it can be used for an industrial-scale application. The irradiation is performed in aqueous media by electron beam without a prorad (sensitizer) at a dose of 200 kGy (20 Mrad) or in the presence of n-butyl acrylate at considerably lower doses, typically 15 kGy. The cross-linked film exhibits physical properties comparable to those obtained from sulfur cured (vulcanized) film. As an alternative, the addition of a variety of chloroal-kanes makes it possible to achieve a maximum tensile strength with radiation doses of less than 5 Mrad (50 kGy). ... 

Irradiation of carbon-black-reinforced polychloroprene compounds produced a maximum tensile strength of 20 MPa (2,900 psi) at a dose of 20 Mrad (200 kGy), which is a value obtained typically from chemically cured compounds. The addition of 20 phr of N,N -hexamethylene-bis methacrylamide as a prorad in the above compound produced a tensile strength of 18 MPa (2,610 psi) at a dose of 7 Mrad (70 kGy). Further addition of 6 phr of hexachlo-roethane caused the deterioration of the tensile strength by 50% at the 7 Mrad (70 kGy) dose. ... 

The temperature at which the film acquired resistance to disintegration by stressing in ethyl acetate and which corresponded to the attainment of maximum tensile strength he defined as the fusion point. ... 

The critical temperature at which 5% maximum tensile strength (5% TS) is achieved. 

In considering true transition points we have considered only one, the liquid/ solid point, to be of practical significance. The other two points considered to be of practical importance—namely, the attainment of 5% and 90% maximum tensile strength—we have called critical points as opposed to transition points. We have not been able, as yet, to find simple reliable tests to replace tensile measurements. 

Sears and Darby (7), in an extensive investigation of the plasticization of bisphenol A polycarbonate, reported that the tensile strength and modulus were increased somewhat and the elongation decreased when some plasticizers were present in relatively small amounts. According to a curve which showed the effect of one of these (iV-ethyl-0//>-toIuenesulfonamide) on film tensile properties, the maximum tensile strength and modulus occurred at an additive concentration... 

A safety factor of 4 1 needs to be applied for pressure-containing components - body wall thickness, closed bonnet wall thickness, bonnet bolts and bonnet bolt threads in body. These components can be stressed to maximum 25% of their nominal maximum tensile strength. 

Fig. 7.25 An axisymmetric particle freely rotating in a simple shear field. The force F exerted hy one half of the particle on the other is zero when the main axis is perpendicular to the flow direction it reaches a maximum tensile strength at 45° and it drops to zero at 90°. Then at 135° it will reach maximum compression and return to zero at 180°. If the ellipsoid is at a certain angle to the direction of shear, the same phenomenon takes place, except that the tensile and compressive forces will he smaller and the particle will rotate and wobble. If the agglomerate is spherical it will smoothly rotate and a maximum tensile strength will be generated along an axis at 45° to the direction of shear.

Several saturation regions can be identified on this curve. S<0,3 represents a pendular saturation state or bridging range. For S>0,8 no liquid bridges exist in the capillary state and ends when the first liquid bridges form between the particles. The relation between maximum tensile strength and the saturation of the cake with the special case of the capillary entry pressure can be written as follows (9,10) ... 

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