Truss Calculations with MD Solids Principles of EngineeringTM Lesson 5.1 - Statics Forging new generations of engineers Project Lead The Way, Inc. Copyright 2007
Truss Calculations with MD Solids
Trusses Enter the information into MD Solids. Before you press “Compute” , try to predict which members are in compression and which are in tension.* *If necessary, refer to the wide variety of “MD Solids Help Documents” included in the MD Solids software to help you get started.
Trusses Notice the gold colored members labeled with a (C) are in compression, and the blue colored members labeled with a (T) are in tension. Did you guess correctly?
Trusses Try to predict which members here are in tension and which are in compression.
Trusses The members in purple are in neither tension or compression. Sometimes, additional members do not help to support a load. These are called zero-force members.
Trusses Try to predict which members here are in tension and which are in compression.
Trusses Compare your predictions with the solution.
Trusses
Trusses
Trusses Solve for the force in each member of the truss in this example to find whether the members are in tension or compression. Use MD Solids software. Start by replacing the supports with reaction forces: A C 3m 4m D B 300 N 200 N
Trusses Here the supports have been replaces with reaction forces: 4m CY 300 N 200 N 3m CX AY
This is how the problem looks when entered into MD Solids. Trusses This is how the problem looks when entered into MD Solids.
The solution shows forces in each member and at each support. Trusses The solution shows forces in each member and at each support.
Trusses For of the following trusses: Replace the supports with the appropriate reaction forces. Predict which beams would be in tension, which would be in compression, and which would be supporting the most force. Draw the truss in MD Solids. Record the forces at the supports and in each beam. Were your predictions correct?
Trusses #1 • 3 ft 4 ft 60 lbs 80 lbs • • • • • 2 ft 500 lb #2
Trusses 200 N 5 kN* 7 kN* 3 m 4 m #3 2 m 3 m 3m #4 • • • • • 3 m 5 kN* 4 m 7 kN* #3 2 m • • • 3 m 3m 200 N • • #4 * 1 KN = 1000N, therefore 5kN = 5000N
Trusses Solution for #1
Trusses Solution for #1
Trusses Solution for #2
Trusses Solution for #2
Trusses Solution for #3
Trusses Solution for #3
Trusses Solution for #4
Trusses Solution for #4