CE 442 Assignment 2
Due 1/26/2006 Thursday 1:00 pm.
PROBLEMS 2.1, 2.2, 2.3
All problems are to be done according to the AISC Steel Construction Manual, 13th Edition. Assume fastener strength is adequate and does not control. All holes are standard holes. Values of yield stress FY and tensile strength Fu are available in AISC p. 2-39. Where needed, assume distances from center of hole to end of piece are 1-1/2 in. When the load is transmitted through some but not all cross-sectional elements be sure to use the correct reduction coefficient U according to AISC D3.3. 2.1 An L 5x 3 x 1/2 angle, as shown in the accompanying figure, is to carry a tension load T that is comprised of 10 kips dead load and 70 kips live load. Using one gage line of holes for 7/8 -in.-diameter bolts in each leg, what would be the minimum stagger s1 required to accomplish safety with regard to net section fracture? Consider the load to be transferred by bolts in the 5-in. leg, while the hole in the 3-in. leg is an open hole (i.e., does not transmit the tensile load). Neglect block shear rupture. Use A572 Grade 50 steel. The gage line distance (i.e. the distance from the outside corner of angle to the center of hole) is 3 inches for the 5” leg and 1.75 inches for the 3” leg. (a) use LRFD (b) use ASD. Assume s2=3.0 in.
2.2 Determine the tensile load (80% live load; 20% dead load) permitted by AISC for a single channel C10x25 fastened to a 5/8-in. gusset plate as shown. Neglect block shear rupture. Use A36 steel and assume holes are for ¾-in. diameter bolts check gross section yielding and net section tensile fracture. (a) use LRFD (b) use ASD.
2.3 Given the splice shown in the accompanying figure: Determine the maximum capacity T (25% dead load, 75% live load) based on the A36 steel plates having holes arranged as shown, assuming that the spacing s1 and s2 are large enough such that net section fracture across three holes with stagger does not control. What minimum value of s should be specified to provide the computed maximum capacity T, if the final design is to have s1 = s2 = s? Neglect block shear rupture. (a) use LRFD (b) use ASD. The 5/16” plates are connection plates subject to the limitation of net area according to AISC J4.1.
