Nielsen Lawrence E Mechanical properties of polymers and composites nielsen doc

... dependence on temperature and time of the properties of polymers compared to those of other materials such as metals. This strong dependence of properties on temperature and on how fast the ... with decreasing tem- perature Finally, at some rather small temperature range, Tg, the rate of further change exceeds the time scale of measurement. The hypothetical glass temp...

Ngày tải lên: 27/06/2014, 17:20

... Lawrence E. Mechanical properties of polymers and composites / Lawrence E. Nielsen. Robert F. Landel. — 2nd ed., rev. and expanded. p. cm. — (Mechanical engineering ; 90) Includes bibliographical references ... Nonlinear Response A. Strain dependence of stress relaxation B. Stress dependence of creep VI. Effect of Pressure YLJ. Thermal Treatments VII). Effect of...

Ngày tải lên: 22/03/2014, 12:20

... Nonlinear Response A. Strain dependence of stress relaxation B. Stress dependence of creep VI. Effect of Pressure YLJ. Thermal Treatments VII). Effect of Molecular Weight: Molecular IX. Effect of ... properties of polymers and composites / Lawrence E. Nielsen. Robert F. Landel. — 2nd ed., rev. and expanded. p. cm. — (Mechanical engineering ; 90) Includes bibliograph...

Ngày tải lên: 22/03/2014, 13:20

... entropy become exponentially slower with decreasing tem- perature Finally, at some rather small temperature range, Tg, the rate of further change exceeds the time scale of measurement. The hypothetical ... glasses are examples of such materials. They have only one of each of the three kinds of moduli, and since the moduli are interrelated, only two moduli are enough to describe...

Ngày tải lên: 26/06/2014, 23:20

... Halle-Wittenberg Merseburg, Germany A. Hiltner Department of Macromolecular Science and Engineering, and Center for Applied Polymer Research Case Western Reserve University Cleveland Ohio ... [23]. The contrast is between extensive parallel lamellar stacks for extended molecules and regular divergence of adjacent chainfolded lamellae as in poly- ethylene and other spherul...

Ngày tải lên: 04/06/2014, 14:26

... holocellulose content seems to decrease from the outer layer to the inner layer, it was not significantly different between the middle and inner layers. Low holocellulose content in the epidermis ... internode number sections (bottom, middle and top). The second and third internodes in each section were selected for physical and mechanical properties determination. The moistur...

Ngày tải lên: 22/02/2014, 09:20

... change to account for the tensile component of stress rather than for the shear component. The temperature dependency of the yield stress can be determined from the tem- perature dependency of ... Calculating shear and tensile properties above the glass transition is more difficult because polymers are viscoelastic and therefore very time-dependent. Our models are static...

Ngày tải lên: 01/04/2014, 00:20

... depends on the cooling rate, the time required exceeds the experimental time available and the melt becomes a polymer glass. The temperature at which this occurs depends on the cooling rate and ... 2 DEFORMATION OF THERMORHEOLOGICAL SIMPLE MATERIALS The stress dependence of the single relaxation time is best demonstrated in creep tests at different stress levels. At low stresses, the...

Ngày tải lên: 09/03/2014, 00:20

... intercept. The slope of the line indicates the degree of myocardial stiffness or elastance (like the elastance of a spring) at the peak of contraction (end-systole) and is therefore called E es ... Figure 10. We see that in the panel on the left that the actual amount of pressure generated by the ventricle and the stroke volume are different in the three cases, although w...

Ngày tải lên: 22/02/2014, 09:20

... Inc. whichisgivensimplybyÀðC A ÀC B Þ=r 0 ,thediffusionflux,J,maythenbe expressedas J¼D 0 exp Àq kT  dC dx  ð2:9Þ IfwescalethequantityqbytheAvogadronumber,thentheenergyterm becomesQ¼N A qandR¼kN A .Equation(2.9)maythusbeexpressedas J¼ÀD 0 exp ÀQ RT  dC dx  ð2:10Þ IfwenowsubstituteD¼ÀD 0 exp ÀQ RT  intoEq.(2.10),weobtainthe usualexpressionforJ,i .e. ,Jisgivenby J¼ÀD dC dx ð2:11Þ Theab...

Ngày tải lên: 23/12/2013, 00:15