The document discusses various structural analysis concepts including trusses, frames, and machines. It defines trusses as structures composed of slender members joined at their endpoints that lie in a single plane. Two common methods for analyzing trusses are presented: (1) the method of joints, which involves solving equilibrium equations at each joint; and (2) the method of sections, which involves cutting a section and applying equilibrium equations to the cut forces. The document also discusses analyzing frames using a similar process of applying equilibrium to members, and defines machines as mechanisms used to change the magnitude and direction of forces.

1. TRUSSES, FRAMES AND MACHINES
S VENKAT RAMANA
UNIT-1
STRUCTURAL
ANALYSIS

2. UNIT 1
 CONTENTS
1. BASIC STRUCTURAL ANALYSIS
2. TRUSSES
3. TRUSSES ANALYSIS BY METHOD OF JOINTS
4. TRUSS ANALYSIS BY METHOD OF SECTIONS
5. ZERO FORCE MEMBERS
6. FRAMES AND MACHINES

3. ENGINEERING
MECHANICS
DYNAMICS
(BODY IS IN
MOTION)
KINEMATICS
(FORCES CAUSING
THE MOTION IS NOT
CONSIDERED)
KINETICS
(FORCES CAUSING
THE MOTION IS NOT
CONSIDERED)
STATICS
(BODY IS AT REST)

4. BASIC STRUCTURAL ANALYSIS
 STRUCTURAL ANALYSIS IS THE VERY BASIC ELEMENT REQUIRED TO PERFORM
STRUCTURAL DESIGN, WITHOUT STRUCTURAL ANALYSIS STRUCTURE CANNOT
BE DESIGNED.
 IN STRUCTURAL ANALYSIS, WE DETERMINE THE MAGNITUDE OF INTERNAL
FORCES DEVELOPED IN MEMBERS OF STRUCTURE DUE TO APPLICATION OF
EXTERNAL LOAD.

5. BASIC STRUCTURAL ANALYSIS

6. BASIC STRUCTURAL ANALYSIS
1
• EQUILIBRIUM CONDITION
2
• SUPPORTS
3
• STATICALLY DETERMINATE AND
INDETERMINATE STRUCTURES

7. BASIC STRUCTURAL ANALYSIS

8. EQUILIBRIUM EQUATIONS

9. EQUILIBRIUM EQUATIONS

10. SUPPORT REACTIONS

11. SUPPORT REACTIONS

12. SUPPORT TYPES

13. SUPPORT TYPES

14. SUPPORT TYPES
HINGE SUPPORT ROLLER SUPPORT

15. TRUSS
A truss is a structure composed of slender members joined together at their end points.
Planar trusses lie in a single plane.
Typically, the joint connections are formed by bolting or welding the end members together to a
common plate, called a gusset plate.
INTERNAL EQUILIBRIUM
TRUSS TRUSS

16. TYPES OF TRUSSES

17. ASSUMPTIONS IN A TRUSS

18. MATH OF TRUSS

20. EXTERNAL STABILITY OF TRUSS

21. EXTERNAL STABILITY OF TRUSS

22. RULES FOR METHOD OF JOINTS
 1. First step is to determine the support reactions using equilibrium equations.
 2. We do not know nature of force in member, so, let us consider the force in the
member to be tension.
 3. In the next step, select a joint with only two unknowns and one known force (Since
only two equations can be used).
 4. Repeat the procedure until you determine the magnitude and nature of forces in all
the members.
1
2
3

23. METHOD OF JOINTS Q-1
STEP-1
STEP-2
Determine the magnitude of
forces in all the members of a
given truss using method of
joints?

24. STEP-
3
STEP-
4

25. METHOD OF JOINTS Q-2
Determine the magnitude
of forces in 1,2,3
members of a given truss
using method of joints?
I

26. STEP-2
STEP-3

27. STEP-
4

28. HOME WORK
METHOD
OF
JOINTS

29. HOME WORK
METHOD
OF
JOINTS

30. METHOD OF SECTIONS Q-1

31. Choose either left side or right side of the cut section, to determine the magnitude
of given forces.
As we have chosen left side of section, we will apply equations Fx=0 and Fy=0 for
these set of forces on left side and forces on right side has to be neglected .
Here we have taken left side of truss,so, moment has to taken in right side portion
only.
While taking moment, consider a point where we have only one unknown.

32. METHOD OF SECTIONS Q-2

34. HOME WORK
METHOD
OF
SECTIONS

35. ZERO FORCE MEMBERS
When magnitude of load on member is zero, then you call the member as a zero force member.
Zero-force members are used to increase stability and rigidity of the truss, and to provide support for
various different loading conditions.
Support reactions should also be considered as a member, while determining zero force members.

36. CASE 1: If a joint has only two
members, without any external load
acting on it and both the members are
non-collinear, then both the members are
zero force members.
CASE 2: If a joint has three members,
without any external load acting on it
and two of the members are collinear
and third member is at some angle to
other two members, then third
members are zero force members.

38. HOME WORK
ZERO
FORCE
MEMBERS

39. FRAMES AND MACHINES

40. Difference between Truss and Frame

41. STEPS TO ANALYSE A FRAME
1. Find the reaction forces at supports using
equilibrium equations
2. Split the frame into separate members
3. Choose one member, where using
equilibrium equations the reaction forces
at pin joints can be found.
4. Repeat the same, to find all the unknown
reactions at pins.

42. STEPS TO ANALYSE A FRAME
1. Find the reaction forces at supports using
equilibrium equations
2. Split the frame into separate members
3. Choose one member, where using equilibrium
equations the reaction forces at pin joints can
be found.
4. Repeat the same, to find all the unknown
reactions at pins.

43. FRAMES Q-1

44. FRAMES Q-1

45. FRAMES Q-1

46. FRAMES Q-2
STEP-1: Find the reaction forces at supports using
equilibrium equations.

47. FRAMES Q-2
STEP-2: Split the frame into separate members
STEP-3: Choose one member, where using C.O.E the reaction forces at pin joints can be found.

48. FRAMES Q-2
STEP-4: Repeat the same, to find all the unknown reactions at pins.
Substitute By value in eq’n 1 to find Cy

49. MACHINES

50. MACHINES Q-1
STEP-1
STEP-2

51. STEP-
3
STEP-4 STEP-5

52. MACHINES Q-2

53. MACHINES Q-2

54. HOME WORK
FRAMES
&
MACHINES

55. HINTS