The perfect power point presentation slides for Truss
- 1. Course Name: Engineering Materials and Mechanics COURSE CODE : CV1001 CREDITS : 04 MODE OF DELIVERY : OFFLINE FACULTY : DR. GAURAV SANCHETI EMAIL-ID : gaurav.sancheti@jaipur.manipal.edu MODULE : 4 DATE OF DELIVERY : 2023 B.TECH. FIRST YEAR ACADEMIC YEAR: 2023-2024 1
- 2. Topics to be covered Relevant Course Outcome 2 • Analysis of truss by method of Joints • Analysis of Truss by method of Sections • Degree of freedom of a structure The students will be able to: • Students will be able to analyze the truss and calculate the forces in the truss members • Calculate the degree of freedom of a 2D structure
- 3. ▪ A truss is an assembly of structural members connected at joints. No member is continuous through a joint. ▪ Forces acting at the member ends, reduce to a single force and no couple. Only two force members are considered. ▪ Most structures are made of several trusses joined together to form a space framework TRUSS 3
- 4. ▪ Each truss carries those loads which act in its plane and may be treated as a two- dimensional structure. ▪ When forces tend to pull the member apart, it is in tension. When the forces tend to compress the member, it is in compression 4 TRUSS
- 5. Thursday, 28 September 2023 5
- 6. Thursday, 28 September 2023 6
- 7. Thursday, 28 September 2023 7
- 8. Thursday, 28 September 2023 8
- 9. Thursday, 28 September 2023 9
- 10. Thursday, 28 September 2023 10
- 11. Overall equilibrium:- Q.2 Determine the forces in the members in the following truss 11 PROBLEMS ON METHOD OF JOINTS
- 12. 12 PROBLEMS ON METHOD OF JOINTS
- 13. • We assumed that all the forces in the members were tensile. But we got some of them negative. So, the negative sign indicates that the forces in the members are compressive 13 FAB=8.84kN (T) FBC=10.62kN (C) FAC=2.13kN (C)
- 14. 14 PROBLEMS ON METHOD OF JOINTS Q.2- Determine the force in each member of the roof truss shown in the fig. State whether the members are in tension or compression. The reactions at the supports are given
- 15. 1 5 PROBLEMS Q.2. SOLUTION Only the forces in half the members have to be determined as the truss is symmetric with respect to both loading & geometry
- 16. 16 Q.2. SOLUTION
- 17. 17 Q.2. SOLUTION
- 18. Q.3Using the method of joints, indicate all the members of the truss that have zero force. PROBLEMS ON METHOD OF JOINTS 18
- 21. 21 Analysis of Trusses by the Method of Sections • When the force in one or a very few members are desired, the method of sections works well. • To determine the force in member BD, pass a section through the truss as shown and create a free body diagram for the left side (or right side). • With only three members cut by the section, the equations for static equilibrium may be applied to determine the unknown member forces, including FBD.
- 22. 22 PROBLEMS ON METHOD OF SECTIONS Q.1 Determine the force in members CF and GC of the roof truss. State whether the members are in tension or compression. The reactions at the supports have been calculated.
- 23. 23 PROBLEMS Q.1 SOLUTION The free-body diagram of member CF can be obtained by considering the section a-a,
- 25. Q 2 Determine the force in member GF and GD of the truss. State whether the members are in tension or compression. The reactions at the supports have been calculated PROBLEMS OF METHOD OF SECTION 25
- 26. Q.2 SOLUTION PROBLEMS 26 The distance EO can be determined by proportional triangles or realizing that member GF drops vertically 4.5 – 3 = 1.5m in 3m. Hence, to drop 4.5m from G the distance from C to O must be 9m
- 30. Degrees of Freedom 30 • Each structure transfers the forces of it from top to bottom into the foundations. • The foundations are idealized as supports in structural engineering. • They are to be understood as degrees of freedom, and thus form the boundary conditions for a structure. • That is to say, they prevent the displacement or rotation in a certain direction, so that no deformation can occur. • Depending on the definition, supports can restrict certain degrees of freedom.
- 31. Degrees of Freedom in 2D system 31 • A planar structure (2D) has three possibilities of movement (degrees of freedom). ➢ Displacements in the horizontal X-direction ➢ Displacements in the vertical Z-direction ➢ As well as one rotation about the global Y-axis.
- 32. 32 Degree of Freedom • Provide resistance to vertical forces only. • Degree of Freedom = 2 (Non-resistive to horizontal force and rotation) • Provide resistance to vertical and horizontal forces. • Degree of Freedom = 1 (Non-resistive to rotation) • Provide resistance to vertical and horizontal forces and rotation. • Degree of Freedom = 0
- 34. 34 Thank you..!