Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Bloque A. Sistemas isostáticos reticulados planos. 
Solid Mechanics Block A. Internal forces. Diagrams. 
Degree in Architecture. San Pablo CEU University – Institute of Technology.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout. 
Note that the 50 kN load that rests on the hinge can be located on any of the three systems that converge at the hinge.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout. 
As the hinge bonds both horizontal and vertical movement of the three solids that meet on it, two unknowns appear at point “C” on each of the three subsystems.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout. 
As the hinge bonds both horizontal and vertical movement of the three solids that meet on it, two unknowns appear at point “C” on each of the three subsystems. 
Vertical movement is the only one linked by the roller at E, so just one reaction will appear on each of the solids that meet at that point.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout. 
As the hinge bonds both horizontal and vertical movement of the three solids that meet on it, two unknowns appear at point “C” on each of the three subsystems. 
Hint: 
If unknowns are positive you’ll always obtain the correct sign in the result. 
Vertical movement is the only one linked by the roller at E, so just one reaction will appear on each of the solids that meet at that point.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout. 
If any of the subsystems is a 3-unknown one, this will mean that it’s a statically determiate one and it’s reactions don’t depend on the behaviour of the rest of the solids.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout. 
If any of the subsystems is a 3-unknown one, this will mean that it’s a statically determiate one and it’s reactions don’t depend on the behaviour of the rest of the solids. 
System CDE meets this condition, so we’ll solve it in first place.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
1 – General layout.
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem    33333310003010031003
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem    33333310003010031003
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem   
 
  
3 3 
3 
3 3 
3 100 
0 
3 
0 
1003 
100 
3
Solid Mechanics – Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem 
    
 
     
3 3 
3 
3 3 
3 100 
0 
3 
0 
100 3 
100 
3 
     3 4 3 4 
0
Solid Mechanics – Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem 
    
         
    
50 0 50 
100 
100 3 50 2 0 100 
3 
100 100 
0 
3 3 
    
 
     
3 3 
3 
3 3 
3 100 
0 
3 
0 
100 3 
100 
3
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem 
Subsistema 4 
   50050100100350201003100100033    33333310003010031003
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem   1122436035341000232500231212
Solid Mechanics – Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem 
   
     
  
        
     
  
2 2 
2 2 
2 
2 
4 3 340 
4 3 0 
590 
0 73 75 8 
90 
15 
250 6 
      
      
  1 1 
2 2 
4 3 60 3 
5 
3 4 100 0 
2 
3 250 
0 
2 3 
1 2 1 2    
Solid Mechanics – Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem 
   
     
  
        
     
  
2 2 
2 2 
2 
2 
4 3 340 
4 3 0 
590 
0 73 75 8 
90 
15 
250 6 
      
      
  1 1 
2 2 
4 3 60 3 
5 
3 4 100 0 
2 
3 250 
0 
2 3 
1 2 1 2    
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem     8606806035810002332500223325060323
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem 
    860680603581000233250500625223832505906037375238
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Exercise 1 - Reactions on each subsystem
Solid Mechanics – Academic Year 2014/2015 
Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 
Bloque A. Sistemas isostáticos reticulados planos. 
If you want to learn how to draw internal force diagrams for this example go for it on Part 2. 
Solid Mechanics Block A. Internal forces. Diagrams. 
Degree in Architecture. San Pablo CEU University – Institute of Technology.

Solid Mechanics. Reactions and internal force diagrams. Step by step example. part 1

  • 1.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Bloque A. Sistemas isostáticos reticulados planos. Solid Mechanics Block A. Internal forces. Diagrams. Degree in Architecture. San Pablo CEU University – Institute of Technology.
  • 2.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout.
  • 3.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout.
  • 4.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout. Note that the 50 kN load that rests on the hinge can be located on any of the three systems that converge at the hinge.
  • 5.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout. As the hinge bonds both horizontal and vertical movement of the three solids that meet on it, two unknowns appear at point “C” on each of the three subsystems.
  • 6.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout. As the hinge bonds both horizontal and vertical movement of the three solids that meet on it, two unknowns appear at point “C” on each of the three subsystems. Vertical movement is the only one linked by the roller at E, so just one reaction will appear on each of the solids that meet at that point.
  • 7.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout. As the hinge bonds both horizontal and vertical movement of the three solids that meet on it, two unknowns appear at point “C” on each of the three subsystems. Hint: If unknowns are positive you’ll always obtain the correct sign in the result. Vertical movement is the only one linked by the roller at E, so just one reaction will appear on each of the solids that meet at that point.
  • 8.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout. If any of the subsystems is a 3-unknown one, this will mean that it’s a statically determiate one and it’s reactions don’t depend on the behaviour of the rest of the solids.
  • 9.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout. If any of the subsystems is a 3-unknown one, this will mean that it’s a statically determiate one and it’s reactions don’t depend on the behaviour of the rest of the solids. System CDE meets this condition, so we’ll solve it in first place.
  • 10.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 1 – General layout.
  • 11.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem    33333310003010031003
  • 12.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem    33333310003010031003
  • 13.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem      3 3 3 3 3 3 100 0 3 0 1003 100 3
  • 14.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem           3 3 3 3 3 3 100 0 3 0 100 3 100 3      3 4 3 4 0
  • 15.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem                  50 0 50 100 100 3 50 2 0 100 3 100 100 0 3 3           3 3 3 3 3 3 100 0 3 0 100 3 100 3
  • 16.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem Subsistema 4    50050100100350201003100100033    33333310003010031003
  • 17.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 18.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 19.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem   1122436035341000232500231212
  • 20.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem                          2 2 2 2 2 2 4 3 340 4 3 0 590 0 73 75 8 90 15 250 6               1 1 2 2 4 3 60 3 5 3 4 100 0 2 3 250 0 2 3 1 2 1 2    
  • 21.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem                          2 2 2 2 2 2 4 3 340 4 3 0 590 0 73 75 8 90 15 250 6               1 1 2 2 4 3 60 3 5 3 4 100 0 2 3 250 0 2 3 1 2 1 2    
  • 22.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 23.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 24.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 25.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 26.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem     8606806035810002332500223325060323
  • 27.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem     860680603581000233250500625223832505906037375238
  • 28.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 29.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 30.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 31.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 32.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Exercise 1 - Reactions on each subsystem
  • 33.
    Solid Mechanics –Academic Year 2014/2015 Prof: Maribel Castilla Heredia @maribelcastilla v.1.0 October 2014 Bloque A. Sistemas isostáticos reticulados planos. If you want to learn how to draw internal force diagrams for this example go for it on Part 2. Solid Mechanics Block A. Internal forces. Diagrams. Degree in Architecture. San Pablo CEU University – Institute of Technology.