Fig. 1. Structure of pentagonal solar heliostat and its geometrical parameters. (a) Photograph of typical pentagonal heliostat;

Fig. 2. Schematic and optical information of a flat mirror shaped into a curved mirror by bolt jacking. (a)Forming schematic; (b) optical information on local triangular microelement surfaces

Fig. 3. Finite element model of reflective mirror jacking forming. (a) Geometric modeling of reflective mirror; (b) support bolt locations for single sub-mirror; (c) triangular mesh of single sub-mirror

Fig. 4. Variation of total slope error S_t and slope error component S_xwith element size for N=8 and d=1200 mm

Fig. 5. Mirror slope error distributions for different number of bolt ring rods N and desired spacing of bolts d. (a) Slope error component S_xdistribution for N=8 and d=1200 mm; (b) slope error component S_y distribution for N=8 and d=1200 mm; (c) slope error distribution for N=4 and d=400 mm; (d) slope error distribution for N=8 and d=400 mm; (e) slope error distribution for N=8 and d=1200 mm

Fig. 6. Variation of total slope error S_twith the number of bolt ring rods N and desired spacing of bolts d when the f= 250 m

Fig. 7. Variation of total slope error S_t with total number of support bolts

Fig. 8. Variations of total slope error S_t with target spherical focal length f. (a) Combination of d=800 mm and number of bolt ring rods N; (b) combination of N=5 and bolt spacing d

Fig. 9. Variations of total slope error S_t with area of reflective mirror at different target focal lengths f when d=400 mm. (a) f=50 m;

Fig. 10. Variations of total slope error S_t with gravity loads. (a) d=400 mm; (b) d=1200 mm

Fig. 11. Clouds of slope error distributions for different number of bolt ring rods N and desired spacing of bolts d at target focal lengths f =750 m under gravity loads along -z axis only. (a) N=4 and d=400mm; (b) N=6 and d=400 mm; (c) N=8 and d=400 mm; (d) N=4 and d=1200 mm; (e) N=6 and d=1200 mm; (f) N=8 and d=1200 mm

Fig. 12. Variations of total slope error S_t with uniform wind loads (including gravity loads). (a) Desired spacing of bolt d=400 mm;

Fig. 13. Clouds of slope error distributions for combined gravity loads and uniform wind loads along -z axis for target focal length f=750 m. (a) N=4 and d=400mm, wind loads 100 Pa; (b) N=6 and d=400 mm, wind loads 250 Pa; (c) N=4 and d=1200 mm, wind loads 100 Pa; (d) N=4 and d=1200 mm, wind loads 250 Pa; (e) N=6 and d=1200 mm, wind loads 250 Pa; (f) N=8 and d=1200 mm, wind loads 250 Pa

Table 1. Total number of mirror support bolts under combinations of different number of bolt ring rods and desired spacing of bolt