Curing stress

There has been extensive work in understanding the origin and level of stresses that develop with coating systems due to curing and/or a thermal gradient. For solventless cured epoxy systems, curing stresses are small (6-8) these can be neglected in the present study since the concern is with solventless cured epoxy systems. 

Uitrasonic Velocity and attenuation factor Modulus of elasticity, geometry, degree of cure, stress-strain state, delamination, density, reinforcement ratio, porosity, flaw size... 

Cure Stress—A residual internal stress produced during the curing cycle of composite structures. Normally, these stresses originate when different components have different thermal coefficients of expansion. 

Cure stress n. Internal stress in cast or molded thermosetting parts, caused by unequal shrinkage in different sections of the parts. Depending on the directions of applied stress in service relative to the principal cure stress, parts may be considerably weaker, than their designers expected them to be. 

Griffin Jr., O. H., Three-dimensional curing stresses in symmetric cross-ply laminates with temperature-dependent properties . Journal of Composite Materials, 17, 1983, 449 63. 

NR,MBT-sulphur cured [stress-reloxation methods] NR,CBS-sulphur cured [stress-relaxation methods ]... 

Kriz RD, Stinchcomb WW (1982) Effects of moisture, residual thermal curing stresses, and mechanical load on the damage development in quasi-isotropic laminates. In Reifsnider KL (ed) Damage in composite materials, ASTM STP 775. American Society for Testing and Materials, Philadelphia, pp 63-80... 

Composite curing stresses, called residual stresses are significant and, in the case of high-modulus composites, can cause part failure on cool-down from cure. These stresses wiU also cause Poisson s ratio strains. 

Assemblies with varying joint gaps should be avoided as much as possible. This practice will avoid uneven stress distributions, irregular pressures in the assembly and internal curing stresses. 

By pointing to social causes, office activists were using stress to argue for the necessity of restructuring office work. The members of the shortlived Nasty Secretaries Liberation Front (who later published Processed World) costumed themselves as computer terminals while handing out leaflets on stress to office workers in San Francisco. The pamphlet insisted that stress is a social disease and it has a social cure. .. Stress is not a result of individual failings. It is the result of an irrational and inhumane society. The solution to stress will not be found in any special seminar or in any special meditation or exercise techniques.. .. it will take a deliberate restmcturing of the social order to reduce it in any real sense. 

The design and analysis of composite structures relies on experimental data. Testing of composites serves a variety of purposes such as the characterization of constituent materials i.e. the fiber, matrix and fiber/matrix interface, verification of the micromechanics analysis including the effects of curing stresses, temperature and moisture, as well as life prediction through accelerated testing[l]. 

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