A B C D

E F50 ft 25 ft 50 ft

25 ft

80 kip at midspan

EI = Constant

CE412 Spring 2014 Lesson 25: Moment Distribution II

LESSON 25: MOMENT DISTRIBUTION METHOD IIMonday, April 07, 2014

LESSON OBJECTIVE1. Use the pinned-end-span short-cut in moment distribution problems.2. Solve moment distribution problems that contain cantilevered ends.

READING AND LESSON SCOPE: Hibbeler (8th edition) Sections 12-3, 12-4.Note: Hibbeler covers three “stiffness factor modifications”: 1). The pinned-end-span short-cut, 2). Symmetric Beam and Loading, and 3). Symmetric Beam with Anti-symmetric Loading. We will only cover the first one in class. The other two can be handy for special cases, so you should review these because it can simplify some problems (such as the one we will do in class)

FIXED-END MOMENTS FOR TODAY (Complete Chart in the back of Hibbeler)

THE PINNED-END-SPAN SHORT-CUT IN MOMENT DISTRIBUTIONK=3EI/L

HOMEWORK ASSIGNMENTSolve the rigid-frame highway bridge structure using moment distribution and plot the moment diagram.