ATTEN: Manager Liu
ADD: Longhua Development Zone, Jing County, Hengshui City, Hebei Province
According to the results of preliminary design of P2000, the section layout (default section 2, preliminary design of 2KNSFCAD) was optimized by three iterations, and the difference of weight between the two iterations was less than 3%. The section layout and design internal forces of the "SFAD preliminary design" given in this paper are shown in Fig. 4 and Fig. 5. The vertical displacement of the central node of the space truss is 38mn, and the vertical displacement is 4K under dead load (excluding dead weight). The calculated results are in good agreement with SAF2000. But the vertical displacement of the center node is less than the result of SAP200. Figure 2 Elastic support space truss SAP2000 design cross-section Figure 3 Elastic support space truss SAP200 design internal force unit space truss structure design software Figure 5 Elastic support space truss SFCAD design internal force (unit: k) (grid structure design software 3.2 comparative analysis and validation according to the results of 3.1 "comparison": ” We find that under the circumferential elastic hinged support condition, the preliminary design of SFCAD for SAP2000 is the result of preliminary design; the design internal force of SAP2000 in short span direction is larger than that of SFCAD, and the design internal force of SAP2000 in long span direction is smaller than that of SFCAD.
Reflected in the section selection, SAP2000 designed space truss in the short span direction, especially the lower chord member section is larger than SFCAD designed section in the long span direction is smaller than SFCAD selected section. It can be found that SAP200 selected a large number of section 1, mainly used in tension members, and SFCAD Bay used section 2 as the minimum section. Noodles. The reason is that the slenderness ratio of tie rod in SFCAD should not be less than 1180, which is the same as the limit value of slenderness ratio of compression rod. This is the result that the slenderness ratio of tie rod in SFCAD can be relaxed to 1/250 and the D test design can be recalculated after the slenderness ratio of tie rod in SFCAD is changed to 1/250. The specific internal force and cross-section results are given. Comparing with the results of sAP2000, we find that the maximum deflection of the space truss increases to 40.4mm, and the distance between the space truss and the SAP2000 preliminary design decreases. The design cross sections of the upper chord and the abdominal chord are almost the same as those of the sAP2000. The internal forces of the lower chord are also similar, but the cross sections of the lower chord are still smaller. Except for j, the other cross sections are smaller than the elastic supports of the SAP2 preliminary design of SFCAD. The section of the grid structure is input into SAP2000 for checking calculation, and the maximum deflection of the node center of "SAP2000 Inspection Design" is 52.1 mm00 and the results of "SFCAD Preliminary Internal Force Calculations Almost the Maximum Tensile Pressure in both directions of the upper and lower chords as an example of CAD Preliminary Design" are as follows: the upper chord-154/-83 kN, the lower chord 151/67 kN, and the upper chord-160/-87 kN calculated by SAP2000, and the lower chord-87 kN. String 156/69kN.
In order to verify the reliability of SFCAD, the maximum internal force of the lower chord is calculated by hand as 5.5 x 3.75 of SAP2000, and the design stress of 156 kN is slightly larger than that of 17Nm2. This indicates that the design of SFCAD is unsafe, but there is still a certain safety reserve because the design strength is higher than the actual yield strength of steel. To sum up, the comparison results are acceptable.