Sub- Solid Mechanics
Eccentrically Loaded Columns
Lect. 5 Direct & Bending Stresses
Sanjivani Rural Education Society’s
Sanjivani College of Engineering, Kopargaon-423603
An Autonomous Institute, Affiliated to Savitribai Phule Pune University, Pune
ISO 9001:2015 Certified, Approved by AICTE, Accredited by NAAC (A Grade) & NBA
Department of Civil Engineering
Prepared by:
Dr. Ghumare S. M.
Asso Professor, Civil Engg. Department
Direct and Bending Stress
0
, ,
,
max min 0 b
max min
Max,Min
Eccentric load produces the
Direct stress as well as
bending stress.
σ , =σ ± σ ,
P M
σ , = ± y,
A I
P 6e
σ = 1±
A b
b
P
Direct Stress
A
M
Bending Stress y
I




 
 
 
Prob.1 A hollow Circular column section having external
diameter 300mm and Internal diameter 250mm, carries a vertical
load of 100KN at the outer edge of the column. Calculate the
maximum and minimum intensities of stress.
Given: Ext. dia. D= 300mm,
Int. dia. d = 250mm, P= 100KN
Location- At the outer edge of column
4 4 4 4
6 4
2 2 2 2
2
??
( ) (300 250 ),
64 64
205.86 10
( ) (300 250 ),
4 4
25198.45 ,
300 / 2 150 , 300 / 2 150
max min
σ , σ
To find
I D d
I x mm
A D d
A mm
e mm y mm
 
 

   

   

   
3
2
0
3
6
2
max min 0 max,min
2
max 0
min 0
100 10
, 4.629 /
25198.45
100 10 150
, .150
205.86 10
, 10.929 /
, , . ,
, 4.629 10.929 15.56 / ,
,
b
b
b
b
b
P x
Direct Stress N mm
A
M x x
Bending Stress y
I x
Bending Stress N mm
P M
i e y
A I
N mm



   
  
  
  
 

   
    
  2
4.629 10.929 6.30 /
N mm
   
Problem1 continue…..
Stress Diagram
2
max
2
mi
2
max
2
mi
max 0
max
min 0
m
n
n
in
15.56 / ( )
6.30 / (
15.56 / ( )
6.30 / ( )
,
4.629 10.929
,
4.629 10.
)
929
b
b
N mm C
N mm Compression
N mm Te
N
n
m
s
m T
ion



  

  



 

 
 
 
 
 
Prob.2 A rectangular column of size 240mm x 150mm,is
subjected to a vertical load of 10KN placed at eccentricity of
60mm in a plane bisecting 150mm side. Determine the maximum
and minimum stress intensities in the section.
Given:
Rect. Column = 240x 150mmmm,
Vertical load P= 10KN, ex = 60mm,
Plane bisecting 150mm side. Load cause
the moment @y-y axis. Consider Iyy
3 3
6 4
2
??
150 240
12 12
172.8 10
240 150 36000 ,
60 ,
240 / 2 120
max min
σ , σ
yy
yy
x
To find
DB X
I
I x mm
A x mm
e mm
y mm

 

 

 
3
2
0
3
6
2
max min 0 max,min
2
max 0
min 0
10 10
, 0.278 /
36000
10 10 60
, .120
172.8 10
, 0.417 /
, , . ,
, 0.278 0.417 0.695 / ,
, 0.278 0.
b
b
b
b
b
P x
Direct Stress N mm
A
M x x
Bending Stress y
I x
Bending Stress N mm
P M
i e y
A I
N mm



   
  
  
  
 

   
    
    2
417 0.13 /
N mm
 
Problem 2 continue…..
max 0
m
2
max
2
m
in 0 in
0.695 / ( ),
, 0.278 0.417,
, 0.278 0.417, 0.13 / ( )
b
b
N mm C
N mm T


  
  
   
  

 

Problem 2 continue…..
Prob.3 A hollow Circular steel column having external diameter
200mm and Internal diameter 150mm, carries a vertical load of
80KN at an eccentricity of 50mm. Calculate the maximum and
minimum stress intensities in the section.
Given: Ext. dia. D= 200mm,
Int. dia. d = 150mm, P= 80KN
Eccentricity exx=50mm
4 4
6 4
2 2
2
??
(200 150 ),
64
53.59 10
(200 150 ),
4
13744.5 ,
50 , 200 / 2 100
max min
σ , σ
To find
I
I x mm
A
A mm M P x e
e mm y mm



 

 
 
  
3
2
0
3
6
2
max min 0 max,min
2
max 0
min 0
80 10
, 5.82 /
13744.5
80 10 50
, .100
53.59 10
, 14.9 /
, , . ,
, 5.82 14.9 20.72 / ,
, 5.82 14.9
b
b
b
b
b
P x
Direct Stress N mm
A
M x x
Bending Stress y
I x
Bending Stress N mm
P M
i e y
A I
N mm



   
  
  
  
 

   
    
     2
9.08 /
N mm

Problem 3 continue…..
max 0
max
min 0
2
min
2
20.72 / ( ),
, 5.82 14.9
, 5.82 14.9
9.08 / ( )
b
b
N mm C
N mm T
  

  

   

   
 
Problem 3 continue…..
max 0
m
2
max
2
m
in 0 in
0.695 / ( ),
, 0.278 0.417,
, 0.278 0.417, 0.13 / ( )
b
b
N mm C
N mm T


  
  
   
  

 

Problem 2 continue…..
Next lecture numerical on stresses
at corner of columns
Thank you

Solid Mechanics Numerical on Direct and Bending Strssess.pptx

  • 1.
    Sub- Solid Mechanics EccentricallyLoaded Columns Lect. 5 Direct & Bending Stresses Sanjivani Rural Education Society’s Sanjivani College of Engineering, Kopargaon-423603 An Autonomous Institute, Affiliated to Savitribai Phule Pune University, Pune ISO 9001:2015 Certified, Approved by AICTE, Accredited by NAAC (A Grade) & NBA Department of Civil Engineering Prepared by: Dr. Ghumare S. M. Asso Professor, Civil Engg. Department
  • 2.
    Direct and BendingStress 0 , , , max min 0 b max min Max,Min Eccentric load produces the Direct stress as well as bending stress. σ , =σ ± σ , P M σ , = ± y, A I P 6e σ = 1± A b b P Direct Stress A M Bending Stress y I          
  • 3.
    Prob.1 A hollowCircular column section having external diameter 300mm and Internal diameter 250mm, carries a vertical load of 100KN at the outer edge of the column. Calculate the maximum and minimum intensities of stress. Given: Ext. dia. D= 300mm, Int. dia. d = 250mm, P= 100KN Location- At the outer edge of column 4 4 4 4 6 4 2 2 2 2 2 ?? ( ) (300 250 ), 64 64 205.86 10 ( ) (300 250 ), 4 4 25198.45 , 300 / 2 150 , 300 / 2 150 max min σ , σ To find I D d I x mm A D d A mm e mm y mm                   
  • 4.
    3 2 0 3 6 2 max min 0max,min 2 max 0 min 0 100 10 , 4.629 / 25198.45 100 10 150 , .150 205.86 10 , 10.929 / , , . , , 4.629 10.929 15.56 / , , b b b b b P x Direct Stress N mm A M x x Bending Stress y I x Bending Stress N mm P M i e y A I N mm                               2 4.629 10.929 6.30 / N mm     Problem1 continue…..
  • 5.
    Stress Diagram 2 max 2 mi 2 max 2 mi max 0 max min0 m n n in 15.56 / ( ) 6.30 / ( 15.56 / ( ) 6.30 / ( ) , 4.629 10.929 , 4.629 10. ) 929 b b N mm C N mm Compression N mm Te N n m s m T ion                          
  • 6.
    Prob.2 A rectangularcolumn of size 240mm x 150mm,is subjected to a vertical load of 10KN placed at eccentricity of 60mm in a plane bisecting 150mm side. Determine the maximum and minimum stress intensities in the section. Given: Rect. Column = 240x 150mmmm, Vertical load P= 10KN, ex = 60mm, Plane bisecting 150mm side. Load cause the moment @y-y axis. Consider Iyy 3 3 6 4 2 ?? 150 240 12 12 172.8 10 240 150 36000 , 60 , 240 / 2 120 max min σ , σ yy yy x To find DB X I I x mm A x mm e mm y mm         
  • 7.
    3 2 0 3 6 2 max min 0max,min 2 max 0 min 0 10 10 , 0.278 / 36000 10 10 60 , .120 172.8 10 , 0.417 / , , . , , 0.278 0.417 0.695 / , , 0.278 0. b b b b b P x Direct Stress N mm A M x x Bending Stress y I x Bending Stress N mm P M i e y A I N mm                                 2 417 0.13 / N mm   Problem 2 continue…..
  • 8.
    max 0 m 2 max 2 m in 0in 0.695 / ( ), , 0.278 0.417, , 0.278 0.417, 0.13 / ( ) b b N mm C N mm T                    Problem 2 continue…..
  • 9.
    Prob.3 A hollowCircular steel column having external diameter 200mm and Internal diameter 150mm, carries a vertical load of 80KN at an eccentricity of 50mm. Calculate the maximum and minimum stress intensities in the section. Given: Ext. dia. D= 200mm, Int. dia. d = 150mm, P= 80KN Eccentricity exx=50mm 4 4 6 4 2 2 2 ?? (200 150 ), 64 53.59 10 (200 150 ), 4 13744.5 , 50 , 200 / 2 100 max min σ , σ To find I I x mm A A mm M P x e e mm y mm             
  • 10.
    3 2 0 3 6 2 max min 0max,min 2 max 0 min 0 80 10 , 5.82 / 13744.5 80 10 50 , .100 53.59 10 , 14.9 / , , . , , 5.82 14.9 20.72 / , , 5.82 14.9 b b b b b P x Direct Stress N mm A M x x Bending Stress y I x Bending Stress N mm P M i e y A I N mm                                  2 9.08 / N mm  Problem 3 continue…..
  • 11.
    max 0 max min 0 2 min 2 20.72/ ( ), , 5.82 14.9 , 5.82 14.9 9.08 / ( ) b b N mm C N mm T                    Problem 3 continue…..
  • 12.
    max 0 m 2 max 2 m in 0in 0.695 / ( ), , 0.278 0.417, , 0.278 0.417, 0.13 / ( ) b b N mm C N mm T                    Problem 2 continue…..
  • 13.
    Next lecture numericalon stresses at corner of columns Thank you