Tensile stress-strain properties

In measurement of tensile stress-strain properties, a test piece is stretched to breaking point and the force and elongation are measured at different stages. Tensile strength, elongation at break or work to failure (the area under the stress-strain curve) provide... 

The determination of tensile stress-strain properties is conducted in accordance with ISO 527 [4] and the values that can be obtained are illustrated in Figure 7.1. For weathering tests where cabinet space is restricted some workers have used a tensile impact dumbbell from ISO 8256 [5] with a square central section which allows test pieces to be exposed edge on. The considerable disadvantage is that modulus cannot be measured as there is no parallel gauge length. 

ISO 37 1994 Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties... 

Determination of tensile strength at break, tensile stress at yield, elongation at break, and stress values of rubber in a tensile test Physical testing of rubber Part A2 Method for determination of tensile stress-strain properties... 

Despite the difficulties associated with the BMI/copper laminates (as just discussed), an understanding of their adhesion characteristics remains important. In particular there is an interest in the relationship between adhesive fracture toughness and temperature. This can be approached by use of either test geometry. The fixed arm peel procedure can be conducted at different test temperatures. The tensile stress-strain properties of the peel arm can also be measured at these temperatures and adhesive fracture toughness calculated in the usual manner and plotted against temperature. This can be a time-consuming process that can be overcome by use of a T-peel procedure operating as a temperature scan. 

The mechanical and thermal properties of a range of poly(ethylene)/po-ly(ethylene propylene) (PE/PEP) copolymers with different architectures have been compared [2]. The tensile stress-strain properties of PE-PEP-PE and PEP-PE-PEP triblocks and a PE-PEP diblock are similar to each other at high PE content. This is because the mechanical properties are determined predominantly by the behaviour of the more continuous PE phase. For lower PE contents there are major differences in the mechanical properties of polymers with different architectures, that form a cubic-packed sphere phase. PE-PEP-PE triblocks were found to be thermoplastic elastomers, whereas PEP-PE-PEP triblocks behaved like particulate filled rubber. The difference was proposed to result from bridging of PE domains across spheres in PE-PEP-PE triblocks, which acted as physical crosslinks due to anchorage of the PE blocks in the semicrystalline domains. No such arrangement is possible for the PEP-PE-PEP or PE-PEP copolymers [2]. 

For hardness and tensile stress-strain properties, predictions (sensible or otherwise) of change at ambient temperatures could be made in 90% of the cases using WLF and Arrhenius relations, but the use of DMTA parameters was far less successful. 

In his 1950 review of the history of rubber testing, Buist (IJ observed that prototypes of many of the tests then in use had been tried with varying degrees of success before 1900. and there is no doubt that technologists of that period would still recognize many of the features of the present-day rubber laboratory. The value of tensile stress-strain properties as control measures was appreciated in the late nineteenth century the principles of the indentation hardness test were established before the First World War and the accelerated air-oven aging test dates back at least 80 years. 

Classification and control, headed by hardness, density, tensile stress-strain properties. 

It should be noted that the standard test methods for tensile stress- strain properties, tear strength, rebound resilience, and other dynamic properties provide for high-temperature measurements, preferably at the recommended temperatures of ISO 471. 

ISO 37 Rubber, vulcanized or thermoplastic— Determination of tensile stress—strain properties... 

For instance, the tensile stress-strain properties of a bulk metallic glass (BMG) is shown in Fig. 1.5. 

Naaman, A. E., Homrich, J. R. (1989) Tensile stress-strain properties of SIFCON , American Concrete Institute Materials Journal, 86(3) 244-51. 

For example, Christenson et al. [3,19] performed a detailed study of polyisobutylene-based pressure-sensitive adhesives. Although these authors did not postulate a specific detachment criterion, they did extensive work characterizing the linear viscoelastic properties, the tensile stress-strain properties, and the peel force. In addition, they conducted detailed visualization of the deformation of the adhesive during peel and therefore, could assess the ability to predict the peel force from the mechanical properties of the adhesive and the visually observed detachment strain. In this work, the adhesive consisted of a blend of high and low molecular weight polyisobutylene. They showed that when they used the Giesekus model as the constitutive equation for the adhesive, they could accurately describe the stress-strain curves of the adhesive and the peel force was well predicted by the integral of the stress-strain curve up to the measured detachment strain. Their results are summarized in Table 1. 

Tensile Stress-Strain Properties of Fibers, Reprint T-1, Instron Corporation, Canton, MA, 1958. 

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