Figure 4
The visual consists of two panels labeled “(a)” at the top and “(b)” at the bottom. In panel “(a)”, a three-dimensional surface plot subdivided into a dense grid of small rectangular elements. The surface forms a smooth concave shape with a lowest region at the center. At the center, a dark blue region appears as a circular area. Surrounding this center, the surface shows successive concentric bands that expand outward in a nearly symmetrical pattern. These bands gradually change in shading from the center toward the edges. Along the four edges, the surface rises slightly, and at each of the four corners distinct red regions are visible, marking the highest zones. The transition from the center to the corners occurs through evenly spaced contour-like bands, forming a symmetric pattern about both horizontal directions. The grid lines remain visible across the entire surface, following the curvature and showing slight bending toward the center. On the left side, a vertical color scale labeled “U, U 2” lists values from top to bottom as positive 2.463 e negative 04, positive 1.194 e negative 04, negative 7.554 e negative 06, negative 1.345 e negative 04, negative 2.614 e negative 04, negative 3.884 e negative 04, negative 5.153 e negative 04, negative 6.422 e negative 04, negative 7.692 e negative 04, negative 8.961 e negative 04, negative 1.023 e negative 03, negative 1.150 e negative 03, and negative 1.277 e negative 03. Below the scale, a coordinate indicator shows axes labeled “X” extending towards the lower right side, “Y” extending vertically upward, and “Z” extending towards the lower left side. In panel “(b)”, a graph shows a coordinate plane with a horizontal axis labeled “G subscript int [megapascal]” on a logarithmic scale ranging from 10 to the negative 4 power to 10 to the 4 power with the multiples of 10. The vertical axis is labeled “w subscript max [millimeters]” and ranges from 0 to 2 with an interval of 0.5. A horizontal line labeled “w subscript lim (floor)” runs across the graph at w subscript max equals 0.75. Above this line, several circular markers are positioned near values around 1.7 at G subscript int equals 10 to the negative 2 power, around 1.5 at equals 10 to the 0 power, and around 1.3 at equals 10 to the power of 0. Below the line, markers appear near approximately 0.6 at equals 10 to the 1 power, around 0.3 at equals 10 to the 2 power, and near 0.2 to 0.3 at equals 10 to the 3 power. A straight line labeled “Point-supported” slopes downward from left to right, with text “Y equals 1.175 minus 9.154 times ln (X)” and “R-squared equals 0.901” placed near the line. Two vertical red arrows are drawn: one near G subscript int equals 10 to the negative 2 power extending from approximately 1.7 down to the horizontal line, and another near G subscript int equals 10 to the 3 power extending from approximately 0.3 down to near 0.1. Near the bottom, a slanted blue line connects two points labeled “(4 linear supports)”, positioned around w subscript max equals 0.3 at G subscript int equals 10 to the negative 2 power and near w subscript max equals 0.05 at G subscript int equals 10 to the 3 power. A legend in the upper right shows “q equals 3 kilonewton per meter square” and a marker labeled “Numerical”. Note: All numerical data values are approximated.Deflection analysis in cold conditions, under a short-term distributed accidental load: (a) example of mechanical numerical model for the examined BIPV floor tile (ABAQUS, legend values in m), based on the effective thickness approach and (b) corresponding variation of the expected maximum deflection wmax (in absolute value), as a function of the shear modulus of the encapsulant, Gint. Source: Authors’ own work