Stress-strain results

Table 2. Network characteristics and stress-strain results...

Swelling data and stress-strain results in SBS have shown that Me is approximately the molecular weight between entanglements. Choudhury and Bhowmick [201] have shown in the case of different NR-based TPEs the following relation ... 

Furnace black-reinforced EPDM and NBR blends were compounded with different concentrations of azodicarbonamide foaming agent to produce EPDM and NBR foamed composites. All the mechanical parameters measured were found to decrease as the foaming agent concentration and/or temperature increased. The stress-strain results were discussed with reference to the continuum mechanics theory for compressible materials. 16 refs. 

Describe the importance of relating models to stress-strain results. 

In a later study [56], the effect of gas volume fraction (foam rheology was investigated. Two models were considered one in which the liquid was confined to the Plateau borders, with thin films of negligible thickness and the second, which involves a finite (strain-dependent) film thickness. For small deformations, no differences were observed in the stress/strain results for the two cases. This was attributed to the film thickness being very much smaller than the cell size. Thus, it was possible to neglect the effect of finite film thickness on stress/strain behaviour, for small strains. 

According to Landes and Wei [2], the connection between the steady-state creep rate and the crack-driving force (characterized by K) is derived through the use stress-strain results from elastic-plastic analysis by Hutchinson [9] and Rice and Rosengren [10], According to these models, crack-tip stress and strains in the loading direction (y-direction) are given by Eqn. (6.7). 

Figure 20.7 Tensile stress-strain results for PE and PE/PS physical and reactive blends with 0.3%, 0.7%, 1.0%, and 1.5% catalyst.

Due to the dual filler and crosslinking nature of the hard domains in TPEs, the molecular deformation process is entirely different than the Gaussian network theories used in the description of conventional rubbers. Chain entanglements, which serve as effective crosslinks, play an important role in governing TPE behavior. The stress-strain results of most TPEs have been described by the empirical Mooney-Rivlin equation ... 

The presence of the notches in the Bridgman specimen made interpretation of stress-strain results somewhat uncertain. Therefore, a new specimen was designed that substitutes simple shear for torsion with normal stress on the shear plane. By empirically adjusting distance Ax to a value of 0.25 mm, it was possible to confine all the plastic shear strain to the reduced area, thus making it possible to readily... 

Figure 13.3 Tensile stress-strain results of banana fibers-reinforced polyester composites. Reprinted with permission from [25]. Copyright 2007 Sage Publications.

Each of these steps depends on the process before. The software suite starts with the material selection, in which also an individual material can be dehned. Fiber orientations and the number of plies can be selected in a following step. All material parameters must be chosen before the analysis can start. Six structural analysis modules can be differentiated with the CDS software suite. These solid mechanic modules are thick-walled cylinder, thin plate, thin plate impact-fastener modeling, thick plate, discontinuous tile modeling and compliant beam interlayer analysis. The CDS software suite allows changing the parameters of the manufacturing process or the laminate structure in real time. Four result sections for those parameter changes are provided by the software the effective properties, thermal-processing response, stress-strain results and the failure response. The CDS software suite is a complete analysis tool kit which is easy to use for the client. The software also allows export into an external simulation tool. 

A total of 44 specimens was tested, per processing condition (unpoled or poled-depoled), to failure in 4-point bending. The true failure stress was determined based on the stress-strain results of unpoled and poled-depoled specimens. The strength distribution was characterized using a two-parameter Weibull distribution and maximum likelihood estimators for Weibull modulus (m) and characteristic strength (oo)... 

Comparison of stress-strain results for LIST and CERT. 

Calculations - Using the measured force-displacement data and resulting calculated stress-strain data along with test specimen dimensions, the flexure stress-strain results are calculated as follows. 

Using the flexure stress-strain results, the following flexural properties are determined i) ultimate flexural strength and corresponding strain, ii) fracture flexural strength and corresponding strain, iii) proportional limit flexural stress, iv) elastic modulus in flexure. 

The ambient temperature stress-strain results for the composites with a 1/1 ratio by weight of MEEP to metal alkoxide show that the nature of the metal alkoxide had a significant effect on the physical properties. The stress-strain curves for these samples are... 

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