Nội dung text Steel Design 2.pdf
Euler Buckling Load RECALL: Buckled shape of column is shown by dashed line Theoretical K 0.5 0.7 1.0 1.0 2.0 2.0 Pinned- Pinned Fixed- Pinned Fixed- Fixed Pinned- Pinned Fixed- Pinned Fixed- Fixed Supports Sidesway Translation/Sidesway Prevented Translation/Sidesway Uninhibited Euler Buckling Stress Anyone can build a structure that stands, but it takes an engineer to build one that barely stands. SITUATION 1 A WF steel column 8 m long is pinned at its top and has a fixed base. Due to connecting frames, it is braced at midheight about its weak axis. Use the following values for the effective length factors (fixed translation): K = 1.0 when pinned at both ends K = 0.5 when fixed at both ends K = 0.7 when pinned at one end and fixed at the other WF Column properties: A = 8840 mm2 Ix = 216 x 106 mm4 Iy = 20 x 106 mm4 Euler Critical Buckling Load: Allowable bending stresses: Fbx = 207 MPa, Fby = 258 MPa Compute for the following: 1. critical slenderness ratio of the column a. 35.8 c. 84.1 b. 51.2 d. 168.2 2. critical buckling stress for the column a. 279 MPa c. 70 MPa b. 753 MPa d. 1540 MPa 3. minimum length of the column so that it will not exceed the proportional limit of Fpl = 320 MPa a. 3.7 m c. 7.4 m b. 3.8 m d. 7.5 m
English