ENS 4115 - Advanced Structural Analysis and Design
Building analysis and design.
Submission: before 4.45pm, Friday 20 May 2016. No late submission accepted.
Below frame is part of a steel building. Your task is to complete the preliminary design of the frame. For preliminary design stage, it is accepted that the frame is detached from the remaining structure after load tributary and geometry repetition are considered. Given:
- Bottom ends of columns are submerged in concrete foundation.
- All beams have vertical downward UDL load of 100 kN/m. Two horizontal point loads of 100 kN each at A (pointing to B) and at D (pointing to C).
- Beam length is 6 m. Column height is 4.25 m.
- The frame is semi rigid/rigid frame regarding connection.
1. a. Manually compute and construct the BMD, SFD and AFD for the frame. (Hint: consider the frame in each orthogonal direction. Superpose the directional solutions). b. Model the frame in Strand7, solve it using Linear Static Solver. c. Compare the Strand7 BMD, SFD and AFD outcomes with the manual calculation outcomes. Discuss on the discrepancies.
2. Use ‘Moment amplification method’ to factor the bending moments if needed.
3. Strength design and serviceability design to give the sizes of the beams, columns and the connections at top of frame. It is required that you use only doubly symmetric compact OneSteel 300 Plus UB and UC sections.
4. Revise point 1 (Strand7 approach to obtain diagrams), point 2 and point 3 with the beams and columns self weights are now included.
5. Use ‘Moment redistribution method’ on the top beams. Revise the beam design with the updated bending moments. Report material savings.
6. (This question is not assessed. You are however recommended to attempt for deepening your knowledge). a. Study the collapse mechanism of the frame and compute the load factor . b. Conduct a non-linear push over analysis in Strand7 to obtain the plastic collapse load. c. Compare the load factor from approach in a. and approach in b. Discuss about the discrepancies.