Question

Problem l The beam shown below is laterally braced at D,F and F. The uniform load shown does not include the weight of the beam. Determine whether a W24x 104 ASTM A992 is adequate for bending and shear. P,-12k PL -36k 3k/ft 10 20 30 FIGURE P5.5-15 a) Determine the controlling load combination and calculate Pu (for the concentrated force) and wu (for wo plus beam's selfweight, which is a uniformly distributed load) b) Analyze the beam loaded with the concentrated load (Pu) and the uniform distributed load (wu) as follows Draw shear and moment diagrams to find, Vmax and Mmax (as was done in the previous HW) Set Vu-Vmax, Mu Mmax c) Is the shape compact? Use AISCM Table 1s to answer d) Determine φMp, Lp and Lr, using the AISCM design aids e) Compare the beam's unbraced length (Lb) with Lp and Lr; would the beam fail under yielding or inelastic lateral torsional buckine (LTB) or elastic LT8?: Wh? f) Calculate Cb using factored loads, Provide clear calculations for MA, MB, Mc Indicate location of A, B and C and Mmax on a sketch. g) Determine pMn using the AISCM design charts; what is the unbraced length, Lb?. Provide a copy of the chart used showing your work. Remember, the charts are for Cb 1.0 h) Determine the final value for фМп i) Is the W24 adequate for bending? k) is the beam adequate for shear?

Answer 1

Lp=9.60 ft 23.8 ft For Lb = 20ft , This shape 's Compact Lb-Lp Mp_ -50(289): in-kips F,Zn 14450 (So)(25e)) 20- 9 60 23 8 6 14450 (150 Ipshave have been ips

138 (20) -6 (20 es (108s)+ 3 (io35〉+ 4 (84*) + 3 (495) Since Check shea« LO 2.24 E