RELATIVE VERTICAL AND HORIZONTAL DISPLACEMENTS

The measured relative vertical displacements refer to the relative movement of the inner wythe with respect to the outer wythe. Positive motion represents relative movement of the inner wythe downward with respect to the outer wythe. Relative vertical measurements were measured at the top of each panel near the mid-width and edge of the panel.

The relative horizontal displacement between the two concrete wythes was monitored at 7/8 of the panel height and mid-height at the edge for panels XPS 3 and XPS 4 only. This displacement was also monitored at mid-height for XPS 2. Positive relative motion reflects separation of the wythes from each other.

3.7.1 Panel EPS 1

The center of panel EPS 1 experienced nearly 0.01 inches of elastic shortening during the application of the axial load while the edge of the panel experienced nearly no effect.

Throughout the fatigue cycles, the center of the panel experienced approximately 0.01 inches of relative vertical panel degradation while the edge of the panel experienced nearly half that degradation as shown in Figure 3-47 (a) and (b), respectively. During the application of the higher level fatigue cycle, the center instrument went offline while the panel edge instrument measured increased load effects. Throughout these cycles, the inner wythe experienced greater elastic shortening due to leeward forces and less elastic shortening due to windward forces. As the panel approached failure, the magnitude of panel degradation significantly increased indicating that the inner wythe resisted increased axial load with an increase in lateral load indicating the panel did not experience fully composite behavior.

(a) (b)

Figure 3-47: Relative vertical displacement of EPS 1

3.7.2 Panel EPS 2

Panel EPS 2 experienced a positive relative vertical displacement during the application of the factored gravity loads indicating that the inner wythe experienced a greater level of elastic shortening. Throughout the fatigue cycles, the panel experienced an increase in

relative vertical displacement due to leeward forces and a decrease in relative vertical

displacement due to windward forces as shown in Figure 3-48. Throughout these cycles, the panel experienced significant panel degradation at both the center of the panel and the edge of the panel as shown in Figure 3-48 (a) and (b), respectively. Note that the positive scale of displacement is scaled to 0.14 inches for EPS 2 versus 0.06 inches for other panels due to the significant panel degradation with increased lateral loads.

(a) (b)

Figure 3-48: Relative vertical displacement of EPS 2

3.7.3 Panel XPS 1

The effect of relative vertical displacement for XPS 1 was minimal in comparison to all other panels. XPS 1 experienced some positive relative vertical displacement during the application of the axial load indicating that the inner wythe resisted more axial load than the outer wythe as indicated in the center and edge of the panel as shown in Figure 3-49 (a) and (b), respectively. Throughout the fatigue cycles, the effect on the panel was minimal in comparison with other panels indicating that solid concrete zones increases the degree of composite action.

(a) (b)

Figure 3-49: Relative vertical displacement of XPS 1

3.7.4 Panel XPS 2

Panel XPS 2 experienced approximately 0.05 inches of relative vertical displacement across the panel width due to the application of the gravity loads. Throughout the fatigue cycles, the magnitude of displacement increased due to leeward forces and decreased due to windward forces. The amplitude of displacement variation from push to pull stroke was noticeably higher of other panels. The center of the panel experienced approximately twice the amplitude than the edge of the panel throughout the maximum and minimum loads of a given cycle as shown in Figure 3-50 (a) and (b), respectively.

(a) (b)

Panel XPS 2 experienced nearly 0.01 inches of wythe separation at mid-height due to the application of the gravity loads. Throughout the fatigue regimen, the panel experienced wythe compression due to leeward forces and wythe separation due to windward forces as shown in Figure 3-51. As the lateral load approached 15 kips with factored gravity loads, the wythe separation became non-linear indicating a degradation in composite action. Final panel compression was nearly 0.06 inches at the failure load of 1.2D+0.5Lr+3.2W120.

Figure 3-51: Relative horizontal displacement at mid-height of XPS 2

3.7.5 Panel XPS 3

The measured small positive relative vertical displacements during testing of XPS 3 indicated that the inner wythe experienced slightly more elastic shortening during the application of factored gravity loads than the outer wythe. Throughout the fatigue cycles, measurements at the center of the panel degradation as the relative vertical displacement increased from approximately 0.004 to 0.02 inches as shown in Figure 3-52 (a). During the application of lateral loads, windward forces (negative direction) showed a decrease in the relative vertical displacement while leeward forces (positive direction) showed an increase in

relative vertical displacement as shown in Figure 3-52 (b). The relative vertical displacement degradation at the panel edge throughout the fatigue regimen was greater than at the center of the panel.

(a) (b)

Figure 3-52: Relative vertical displacement of XPS 3

The measurements at 7/8 of the panel height showed the wythes compressed towards each other with the application of the factored gravity loads while the mid height of the panel experienced no motion due to these loads. With the application of lateral loads, the measured values showed that the panel compressed during leeward forces and separated during

windward forces. With increased lateral load cycles, the top of the panel experienced very little degradation while the mid height of the panel did not show any sign of degradation throughout the fatigue regimen as shown in Figure 3-53 (a) and (b), respectively.

(a) (b)

Figure 3-53: Relative horizontal displacement of XPS 3

3.7.6 Panel XPS 4

Positive relative vertical displacements measured during testing of XPS 4 showed that the center of the inner wythe experienced slightly more elastic shortening during the application of factored gravity loads than the outer wythe. Throughout the fatigue cycles, the panel experienced a decrease in relative vertical displacement due to windward forces and an increase in relative vertical displacement due to leeward forces. The panel experienced very little degradation across the panel width throughout the fatigue regimen as shown in Figure 3-54 (a) and Figure 3-54 (b).

(a) (b)

The measurements at 7/8 of the panel height showed the wythes compressed towards each other with the application of the factored gravity loads while the mid height of the panel experienced minimal separation due to these loads. With the application of lateral loads, the measured values showed that the panel compressed during leeward forces and separated during windward forces. While mid-height exhibited a linear behavior throughout testing, the measurements at 7/8 panel height showed a non-linear behavior at the end of the cyclic loading regimen. With increased lateral load cycles, the top of the panel experienced nearly 0.02 inches of degradation while the mid height of the panel showed little degradation throughout the fatigue regimen as shown in Figure 3-55 (a) and (b), respectively.

(a) (b)

Figure 3-55: Relative horizontal displacement of XPS 4