Chapter 10 - Composite Beams
© 2006, 2007, 2008, 2011 T. Bartlett Quimby
As presented in Chapter 1, the homework problems involve the design of elements of three different structures plus some unrelated details. Please see the relevant links below for each structure. When completing the problems, consider both ASD and LRFD design philosophies unless otherwise specified by the instructor. Consider all limit states presented in this and prior chapters. Consider developing a generic spreadsheet that you can apply to similar problems.
Problem M10.1: The floor framing plan depicted in MISCDET_STL 1/S6.2 consists of a flat concrete slab supporting office floor live load and partition loadings. The slab acts compositely with steel joist beams to span the bay shown. The joist beams are supported by girder beams. Note that the shown number of joists per bay is only representative. You may change this to find the best solution.
The objective of this problem is to accomplish the following tasks:
The following criteria are applicable:
All the floor beams in the dormitory building are candidates for composite construction.
Problem D10.1: Repeat Problem D8.1 using 1/2" diameter headed studs with the joists. Assume that the slab is 4" thick and the maximum joist spacing is 6'-0". If you completed problem D8.1, compare the results from this problem with the results from problem D8.1 and comment as appropriate. Assume unshored construction, however assume that the form work will provide lateral support for the beams during construction. Use a construction live load of 20 psf. Complete the following table:
Problem D10.2: Repeat Problem D8.2 using 1/2" diameter headed studs with the beams. If you completed problem D8.2, compare the results from this problem with the results from problem D8.2 and comment as appropriate.
Being an axial force truss system, the tower does not provide us with opportunity to use flexural cover plates nor beam bearing plates. Consequently, there are no assignments for the tower in this chapter.
The principle flexural members in the bridge are the deck beams, girders and end girders. All are statically determinate. They are also relatively short allowing a single wheel to be the defining vehicle load. Use L/260 as the total load deflection limit and L/360 as the live load only deflection limit. Assume the concrete deck is 6 inches thick, the 28-day concrete strength, f'c, is 4,000 psi, and that the beams are shored during construction.
Problem B10.1: Repeat Problem B8.1 using 1/2" diameter headed studs with the beams. If you completed problem B8.1, compare the results from this problem with the results from problem B9.1 and comment as appropriate.
Problem B10.2: Repeat Problem B8.2a using 1/2" diameter headed studs with the beams. If you completed problem B8.2a, compare the results from this problem with the results from problem B8.2a and comment as appropriate.