Adhesion tests fatigue

Tire cords are characterized for their physical, adhesion, and fatigue properties for use in tires. These characterizations are conducted under normal and varying test conditions to predict their performance during tire operation. Various test methods used to characterize tire cords are described. 

ISO 9653 1998 Adhesives - Test method for shear impact strength of adhesive bonds ISO 9664 1993 Adhesives - Test methods for fatigue properties of structural adhesives in tensile shear... 

A SPECIMEN CONFIGURATION FOR TESTING ADHESIVES IN FATIGUE AND CREEP... 

ISO 9664 1993 Adhesives -Test methods for fatigue properties of structural adhesives in tensile shear... 

Adhesives determination of tensile lap-shear strength of rigid-to-rigid bonded assemblies Adhesives diuabUity of stmctural adhesive joints exposure to humidity and temperature under load Adhesives test methods for fatigue properties of stmctural adhesives in tensile shear... 

Static fatigue is the slow growth of a crack under ambient stress and environmental conditions. The static fatigue failure in oxide materials can be accelerated by moisture or hydrogen, which weaken the chemical bonds at the crack tip. This moisture can be supplied by breathing on the films to condense moisture. This moisture condensation method is an easy way to quickly determine if the residual film stresses are high or the adhesion is poor, and the nature (compressive or tensile stress) of the stresses in a film. This moisture condensation is the basis of the bad breath adhesion test (Sec. 12.5.2). 

Adhesion tests may be divided into the methods by which stress is applied to the lilm/coating. Adhesion test methods include tensile tests, peel tests, shear tests, deformation tests, energy deposition tests, fatigue (thermal, mechanical) tests, and many others. Some of these tests are depicted in Figure 12.3. Adhesion testing of thin films on flexible substrates such as webs is a particularly difficult problem.f ... 

Adhesion testing to reflect production, storage, and service environments (temperature, chemical, hunfidity, mechaiucal fatigue, etc.). 

Adhesion test program A program designed to subject the hlm-substrate structure to the stresses (mechanical, chemical, thermal, fatigue) that it might see in subsequent manufacturing and service with adhesion teshng, to ensure the adhesion of the him under those condihons. 

Sorenson, A., Sonic fatigue testing and development of aircraft panels. Symposium on Structural Adhesives and Sandwich Construction. Wright Air Development Center, Wright Patterson Air Force Base, Ohio, 1957. 

The extent of adhesive bond failure under corrosive environments is greatly accelerated when cyclic mechanical stresses are imposed on the adhesive bond during exposure. Three to four orders of magnitude reduction in fatigue life of adhesive bonds is observed for bonds exposed to environment prior to fatigue testing. 

In particular, the techniques based on the termination of certain plies within the laminate has also shown promise. Static tensile tests of [30°/-30°/30°/90°]s carbon-epoxy laminates containing terminals of [90°] layers at the mid-plane show that premature delamination is completely suppressed with a remarkable 20% improvement in tensile strength, compared to those without a ply terminal. Cyclic fatigue on the same laminates confirms similar results in that the laminate without a ply terminal has delamination equivalent to about 40% of the laminate width after 2x10 cycles, whereas the laminates with a ply terminal exhibit no evidence of delamination even after 9x10 cycles. All these observations are in agreement with the substantially lower interlaminar normal and shear stresses for the latter laminates, as calculated from finite element analysis. A combination of the adhesive interleaf and the tapered layer end has also been explored by Llanos and Vizzini, (1992). 

The second class includes tests for ageing, oxygen and ozone attack, adhesion, resistance to wear and tear, fatigue, etc. This class also includes tests under simulated service conditions under laboratory environments and immersion in fluids. These two classes of tests are conducted on vulcanized rubber. 

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