cee 312(4)(structural analysis)
TRANSCRIPT
CEE-312
Structural Analysis and Design Sessional-I
(1.0 credit)Lecture: 4
Bijit Kumar Banik
Assistant Professor, CEE, SUSTRoom No.: 115 (“C” building)
Department of Civil and Environmental Engineering
Analysis and design of an Industrial roof truss sys tem
(4.41) (4.41) (3.53) (3.53) (4.41) (4.41)
(- 5.05)
(- 4.04)(- 3.03) (- 3.03)
(- 4.04)
(- 5.05)
6@6 ft = 36 ft
L0L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
2.94 k2.94 k
(.18
)
(0.6
7) (0.6
7)
(.18
)
(2.1
4)(- 1.32)(- 1.01) (-1.
32)
(- 1.01)
Analysis and design of an Industrial roof truss sys tem
P = (0.07*29.05-2.1)*25.6 = -1.7 psf
For windward surface
For leeward surface
P = -0.7*25.6 = -17.92 psf
We already calculated in lecture-2
Once again what –ve sign means? Suction/Uplift
Wind load calculations
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1R2
H
Wind blows from left to right
Windward side joint loads (U 1 & U2)= 1.7*20*6.86 = 0.23kEnd joint loads [ L 0 & (U3)left ] = 0.23/2 = 0.12kLeeward side joint loads (U 4 & U5)= 17.92*20*6.86 = 2.46kEnd joint loads [ L 6 & (U3)right ] = 2.46/2 = 1.23k
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k
1.23k
1.23k
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1R2
H
–0.23*6.86 –0.23*2*6.86 –0.12*3*6.86 –1.23*(9/10.3)*18 +1.23*(5/10.3)*10–2.46*(9/10.3)*24 +2.46*(5/10.3)*2*(10/3) – 2.46*(9/10.3)*30 +2.46*(5/10.3)*(10/3) – 1.23*(9/10.3)*36 + R1*36 = 0
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k
1.23k
1.23k
∑ML0= 0 +ve
5
9
10.3
95
10.3
R1 = 4.54k
= 4.54k
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
R2 = (9/10.3)*(2*0.12+2*0.23+2*1.23+2*2.46) – 4.54
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k
1.23k
1.23k
∑V= 0
5
9
10.3
95
10.3
R2 = 2.60k
H = (5/10.3)*(2*1.23+2*2.46) – (5/10.3)*(2*0.12+2*0.23)∑H= 0
H = 3.24k
= 3.24k= 2.60k
= 4.54k
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
1
1
∑V = 0(5/10.3)*L0U1+(9/10.3)*0.12 – 2.6 = 0L0U1= 5.14 k (T) 5
9
10.3
∑H = 0
L0L1 +(9/10.3)*5.14 – (5/10.3)*0.12 – 3.24 =0L0L1= 1.19 k (C)
2.60 k
0.12k
L0L1
L0U1
1-1
3.24 k
95
10.3
Wind Load Analysis
∑V= 0
L1U1 = 0
L1L2 = L0L1 = 1.19k (C)
∑H= 0
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
2 2
L1L2
2-2
L0L1=1.19k
L1U1
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
3
3
9
510.3
95
10.3
95
10.3
∑ML0 = 0– 0.23*6.86 + (5/10.3)*U1L2*6 + (9/10.3)*U1L2*(10/3)= 0
U1L2= 0.27 k (T)∑V = 0
(9/10.3)*0.12+(9/10.3)*0.23 + (5/10.3)*U1U2– (5/10.3)*0.27 – 2.60= 0
U1U2= 5.0 k (T)
+ve 3-3
U1
L0 L1 L2
U20.23 k
0.12 k
2.60 k
(10/3)’
1.19k3.24k
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
4 4
∑H = 0
L2L3= 0.95 k (C)
59
10.3
L2L3
4-4
1.19k
L2U20.27k
∑V = 0L2U2 = (5/10.3)*0.27
L2U2= 0.13 k (C)
L2L3 +1.19 – (9/10.3)*0.27 = 0
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
5
5
109
13.45
59
10.3
∑ML0 = 0
(9/13.45)*U2L3*(20/3)+ (10/13.45)*U2L3*12 – 0.23*6.86 – 0.23*2*6.86 = 0
U2L3= 0.35 k (T)∑V = 0(5/10.3)*U2U3+ (9/10.3)*(0.12+0.23+0.23)– (10/13.45)*0.35 – 2.60 = 0
U2U3= 4.85 k (T)
+ve
95
10.3
5-5
L0 L1 L2 L3
U1
U2
U3
0.12 k
2.60 k
0.23 k
0.95 k
2*(10/3)
0.23 k
3.24 k
Wind Load Analysis
(5/10.3)*U5L6+(9/10.3)*1.23 – 4.54 = 0∑V= 0
U5L6 = 7.14k (T)
∑H= 0
L5L6 = 5.64k (C)
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
6
6
59
10.35
910.3
4.54 k
U5L6 1.23k6-6
L5L6(5/10.3)*1.23 – (9/10.3)*7.14 – L5L6= 0
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
7 7
∑H = 05.64k
7 – 7
L4L5
L5U5
∑V = 0
L5U5= 0
L4L5 = 1.19k (C)
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
8
8
59
10.3
9510.3
95
10.3
L6
U5
L5L4
U4
2.46k
1.23k
4.54k
8-8∑ML6 = 02.46*6.86 – (5/10.3)*U5L4*6 – (9/10.3)*U5L4*(10/3)= 0
U5L4= 2.90 k (T)∑V = 0
(9/10.3)*2.46+(9/10.3)*1.23 + (5/10.3)*U4U5– (5/10.3)*2.90 – 4.54= 0
U4U5= 5.61 k (T)
+ve
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
9 9
∑H = 0
L3L4= 3.11 k (C)
∑V = 0L4U4 = (5/10.3)*2.90
L4U4= 1.41 k (C)
L3L4+ (9/10.3)*2.90 – 5.64 = 0
9510.3
5.64k
9-9L4U4
2.90k
L3U4
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
10
10
95
10.3
910
13.459
5
10.3
2.46k
2.46k
1.23k
4.54k
L6L5L4L3
U3
U5
U4
3.11k
10 -10 ∑ML6 = 0
–(9/13.45)*U4L3*(20/3) – (10/13.45)*U4L3*12 + 2.46*6.86 +2.46*2*6.86 = 0
U4L3= 3.78 k (T)∑V = 0(5/10.3)*U3U4 + (9/10.3)*(1.23+2*2.46)– (10/13.45)*3.78 – 4.54 = 0
U3U4= 4.07 k (T)
+ve
Wind Load Analysis
6@6 ft = 36 ft
10 ft
L0 L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
R1
R2
H
0.23k
0.23k
0.12k
0.12k
2.46k
2.46k1.23k
1.23k
59
10.3
95
10.3
= 3.24k
= 4.54k= 2.60k
11 11
∑V = 0
91013
.45
910
13.45
3.11k
11 – 11
0.95k
L3U3
L3
0.35k 3.78k(10/13.45)*3.78 + (10/13.45)*0.35 – L3U3= 0
L3U3= 3.07 k (C)
Wind Load Analysis
(- 1.19) (-1.19) (-0.95) (-3.11) (-5.64) (-5.64)
(5.14)
(5.00)
(4.85) (4.07)
(5.61)
(7.14)
6@6 ft = 36 ft
L0L1 L2 L3 L4 L5
L6
U1
U2
U3
U4
U5
4.54 k2.60 k
(0)
(-0.
13)
(-1.
41)
(0)
(-3.
07)
(0.35)(0.27) (3.7
8)
(2.90)
3.24k
L R
Wind Load Analysis
