Static Tensile Behavior

More recently, Kotek at al. studied the effects of untreated (denoted as Cl) and stearate-treated calcium carbonate particles (denoted as C2) of 1.3 p.m on the tensile properties of P-PP. Moreover, stearate-coated calcium carbonate particles of 0.075 p,m (denoted as C3) are also used (44). The p-nucleating agent employed is based on an amide of dicarboxylic acid. The critical concentration of p-nucleator needed to achieve 61% P-PP is 0.03 wt% on the basis of the XRD analysis. With further increase in the p-nucleator content to 0.1 wt% (supercritical), the p-PP content increases, but very slightly, to 65%. Furthermore, the K value also depends 

In general, the p-PP is mechanically stable up to yield point but transforms to a-phase during necking (24,26,27,44- 7). The strain-induced p a phase 

To get further insight into the deformation mechanisms of (3-PP during drawing, Li et al. employed electron microscopy (scanning electron microscopy, SEM and transmission electron microscopy, TEM) to observe the lamellar stmctural changes 

Sample Strain, % Starting fusion °C P- a- Melting Melting point, point. Jg- Jg- Xp, % % X, %  

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Bogdanovich AE, Karahan M, Lomov SV, Verpoest I. Quasi-static tensile behavior and progressive damage in carbon/epoxy composite reinforced with 3D non-crimp orthogonal woven fabric. Mech Mater 2013 62 14-31. 

We do not have much data on the spall strength of many materials. Even when we do have data, the local conditions and history of that one particular specimen come heavily into play. Table 19.1, however, lists approximate values that can be expected for the spall behavior of several materials of common interest. The values for spall strength shown in Table 19.1 are considerably higher than the equivalent static tensile strengths of these same materials, ranging from a factor of 2.5 to as high as 10. 

During the past six months (October 1989 to March 1990), evaluations of one SiC and two Si N ceramics continued. The tensile strength of GTE s PY6 was measured from temperatures of 20 C to 1400 C, and the tensile stress rupture (static fatigue) behavior of Norton/TRW NT-154 and Hexoloy SA was investigated. In addition, the effect of thermal aging in air on the flexural strength of Hexoloy SA, NT-154, and PY6 was also investigated. 

Karger-Kocsis, J. and Varga, J. (1996) Effects of p-a transformation on the static and dynamic tensile behavior of isotactic pol3 ropylene. J. Appl. Polymer Sci., 62, 291-300. 

Lin and coworkers [41] also investigated the static tensile strength and fatigue behavior of long glass-reinforced semicrystalline polyannide and amorphous polycarbonate composites. The static tensile measurement at various tanperatures and tension-tension fatigue loading tests at various levels of stress amplitudes were studied. 

In actual applications, solder interconnects are often under complex loading conditions (Ref 25). For example, ball grid array (EGA) solder joints may be simultaneously under cyclic shear loading and static tensile (or compressive) loading often with vibration. The deformation behavior and reliability prediction under complex loading conditions warrant further examination. Time and path-dependent creep models are needed for the solder joints under different and often complex loading conditions (Ref 2). 

The present paper is specially focused on the surface mechanieal properties of polypropylene films heterogeneous modified by using acrylic acid as grafting agent in solution. Surface mechanical properties have been measured by nano-indentation techniques and the chemical treatment induced variation of the mean image roughness, reduced modulus and surface hardness have been assessed. Whetha- beneficial bulk mechanical properties remained actually unaffected by surface chemical modification was checked by determining the tensile deformation behavior, static fracture behavior and dart impact response. 

Najafbadi and Yip (18) have investigated the stress-strain relationship in iron under uniaxial loading by means of a MC simulation in the isostress isothermal ensemble. At finite temperatures, a reversible b.c.c. to f.c.c. transformation occurs with hysteresis. They found that the transformation takes place by the Bain mechanism and is accompanied by sudden and uniform changes in local strain. The critical values of stress required to transform from the b.c.c. to the f.c.c. structure or vice versa are lower than those obtained from static calculations. Parrinello and Rahman (14) investigated the behavior of a single crystal of Ni under uniform uniaxial compressive and tensile loads and found that for uniaxial tensile loads less than a critical value, the f.c.c. Ni crystal expanded along the axis of stress reversibly. 

The buffering action of a coating in this situation is determined by the relaxation modulus of the coating material. The relaxation modulus may be measured on a film cast from the material by carrying out tensile-stress relaxation measurements with a suitable apparatus such as a Rheovibron dynamic viscoelastometer operated in a static mode. Figure 13 (inset) displays such measurements for the four coating materials used on the fibers measured in Figure 12. The measurements were carried out at 23 °C at small tensile strains, where the materials exhibit linear viscoelastic behavior. 

For room-temperature applications, most metals can be considered truly elastic. When stresses beyond the yield point are permitted in the design permanent deformation is considered a function only of applied load and can be determined directly from the usual static and/or dynamic tensile stress-strain diagram. The behavior of most plastics is much more dependent on time of application of the load, history of loading, current and past temperature cycles, and environmental... 

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