Deflection time curves

Deflection-time curves for flakeboards are shown in Figure 6. The curves show an initial increase of deflection for both control and acetylated flakeboards, then a stable zone, and finally, for control boards, a steep slope to failure. The study showed that less than mm of deflection was caused by creep due to moisture alone ( U). 

Figure 6--Deflection-time curves of phenol-formaldehyde- (PF-) and isocyanate- (IS-) bonded flakeboards in bending-creep tests under progressive fungal attack by T. palustris (upper) and T. versicolor (lower). = PF control = PF acetylated = IS control O = IS acetylated.

Fig 10. Deflection-time curves for a thixotropic system. The curve marked 0 is a truly exponential return to equilibrium. After waiting for periods of 1, 5, 25 and 125 minutes, the return is slower, not exponential and does end in a fini te deflection,as for instance in the 125 min curve, where the part A B is already parallel to the abscissa. 

A time dependent modulus is then calculated using the extreme fiber stress level for each of the materials at the initial stress value level using the loading-time curve developed. If the deflection at the desired life is excessive, the section is increased in size and the deflection recalculated. By iteration the second can be made such that the creep and load deflection is equal to the maximum allowed at the design life of the chair. This calculation can be programmed for a computer solution. 

Curves of deflection vs. time for two different thicknesses of the PVC/PV Ac copolymer are shown in Figure 15. The upper curve represents two experimental tests on 0.030-inch thick samples. The lower curve represents three tests on the thinner 0.010-inch samples. The difference between the deflection vs. time curves for the two thicknesses is in the direction one would expect if gas accumulation were causing the increased creep rates during irradiation. The two samples show... 

The indentation versus time curves for each scan rate from the contact point to the zero cantilever deflection point cire converted from Figure 9(a) and plotted in Figure 10(a). The indentation versus -Z is given in Figure 10(b), which reveals the viscoelastic effects more clearly. 

The lung volume level for measurement of MEF40% and MEF40%(P) is shown by the dashed vertical line. Point of maximum inspiration is indicated by the zero point on volume axis. The v shaped pen deflection near full expiration on MEFV curve is the one second time marker for measurement of FEV, . The entire expiration-inspiration-expiration maneuver was recorded uninterrupted. 

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