This program is written by salar delavar qashqai Salardqashqai.blogfa.com

1. >> IN THE NAME OF GOD <<
1st order Pushover Analysis of Column subjected to Compression and Tension
Axial load in MATLAB and SeismoStruct (Displacement Control)
The MATLAB Program is Verified by SEISMOSTRUCT v.7.0.1 (Nonlinear Structural Analysis Program)
This MATLAB program is written by Salar Delavar Ghashghaei ‐ Date Of Publication: December/18/2015
E‐mail: salar.d.ghashghaei@gmail.com
Unconfined concrete section model in SeismoStruct and Matlab
Pushover compression and tension axial load (Displacement Control) with SeismoStruct

2. Concrete properties (Mander et al.) in SeismoStruct
Steel properties (Blinear) in SeismoStruct
Section Properties:
b=300;% [mm]
h=300;% [mm]
L=3000;% [mm] Column Length
%As: As1 As2 As3 As4 As5 As6

3. As=[100.528 0 0 0 0 100.528]; % NOTE: As1 & As6 = 2fi8
%d:d1 d2 d3 d4 d5 d6
d=[25 0 0 0 0 275];
Concrete Properties:
fc =25;% [N/mm^2] Unconfined concrete strength
ecu=0.004;% Ultimate concrete strain
Ec=5000*sqrt(fc);
ec0=(2*fc)/Ec;
fct=-0.7*sqrt(fc);% Concrete tension stress
ect1=(2*fct)/Ec;ect2=(2.625*fct)/Ec;ect3=(9.292*fct)/Ec;% Concrete tension
strain
Steel Reinforcing Properties:
fy =400;% [N/mm^2] Yield strength of reinforcing steel
Es =2e5;% [N/mm^2] Modulus of elasticity of steel
fu=1.5*fy;% Ultimate steel stress
ey=fy/Es;% Yeild steel strain

4. esh=0.01;% Strain at steel strain-hardening
esu=0.09;% Ultimate steel strain
Esh=(fu-fy)/(esu-esh);
Analysis Report:
###########################################
# Compression Axial Load‐Displacement Analysis #
###########################################
(+)Increment 1 : Strain: 0.00004 ‐ Displacement: 0.126 ‐ Axial Load: 94.99
(+)Increment 2 : Strain: 0.00009 ‐ Displacement: 0.277 ‐ Axial Load: 206.36
(+)Increment 3 : Strain: 0.00019 ‐ Displacement: 0.563 ‐ Axial Load: 408.95
(+)Increment 4 : Strain: 0.00028 ‐ Displacement: 0.840 ‐ Axial Load: 595.85
(+)Increment 5 : Strain: 0.00037 ‐ Displacement: 1.103 ‐ Axial Load: 764.01
(+)Increment 6 : Strain: 0.00043 ‐ Displacement: 1.288 ‐ Axial Load: 877.58
(+)Increment 7 : Strain: 0.00087 ‐ Displacement: 2.615 ‐ Axial Load: 1565.38
(+)Increment 8 : Strain: 0.00104 ‐ Displacement: 3.122 ‐ Axial Load: 1770.34
(+)Increment 9 : Strain: 0.00117 ‐ Displacement: 3.512 ‐ Axial Load: 1906.15
(+)Increment 10 : Strain: 0.00130 ‐ Displacement: 3.903 ‐ Axial Load: 2022.97
(+)Increment 11 : Strain: 0.00160 ‐ Displacement: 4.800 ‐ Axial Load: 2219.51
(+)Increment 12 : Strain: 0.00200 ‐ Displacement: 6.000 ‐ Axial Load: 2235.40
(+)Increment 13 : Strain: 0.00240 ‐ Displacement: 7.200 ‐ Axial Load: 2235.55
(+)Increment 14 : Strain: 0.00280 ‐ Displacement: 8.400 ‐ Axial Load: 2235.70
(+)Increment 15 : Strain: 0.00320 ‐ Displacement: 9.600 ‐ Axial Load: 2235.85
(+)Increment 16 : Strain: 0.00360 ‐ Displacement: 10.800 ‐ Axial Load: 2236.00
(+)Increment 17 : Strain: 0.00400 ‐ Displacement: 12.000 ‐ Axial Load: 2240.42
+======================+
= Analysis curve fitted =
Displacement Axial Load
(mm) (kN)
‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
1.0e+003 *
0 0
0.0027 2.0134
0.0120 2.2404
+======================+
+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐+
Elastic EA : 753.87 (kN)
Plastic EA : 24.33 (kN)
Unconfined Section Axial Ductility Rito : 4.49
Ultimate Axial Capacity (kN) : 2240.42
+‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐+
######################################
# Tension Axial Load ‐Displacement Analysis #
######################################
(+)Increment 1 : Strain: ‐0.00001 ‐ Displacement: ‐0.030 ‐ Axial Load: ‐11.68
(+)Increment 2 : Strain: ‐0.00112 ‐ Displacement: ‐3.363 ‐ Axial Load: ‐75.48
(+)Increment 3 : Strain: ‐0.00223 ‐ Displacement: ‐6.697 ‐ Axial Load: ‐80.42
(+)Increment 4 : Strain: ‐0.00334 ‐ Displacement: ‐10.030 ‐ Axial Load: ‐80.42
(+)Increment 5 : Strain: ‐0.00445 ‐ Displacement: ‐13.363 ‐ Axial Load: ‐80.42
(+)Increment 6 : Strain: ‐0.00557 ‐ Displacement: ‐16.697 ‐ Axial Load: ‐80.42
(+)Increment 7 : Strain: ‐0.00668 ‐ Displacement: ‐20.030 ‐ Axial Load: ‐80.42
(+)Increment 8 : Strain: ‐0.00779 ‐ Displacement: ‐23.363 ‐ Axial Load: ‐80.42
(+)Increment 9 : Strain: ‐0.00890 ‐ Displacement: ‐26.697 ‐ Axial Load: ‐80.42
(+)Increment 10 : Strain: ‐0.01001 ‐ Displacement: ‐30.030 ‐ Axial Load: ‐80.43
.
.
.
(+)Increment 72 : Strain: ‐0.07890 ‐ Displacement: ‐236.697 ‐ Axial Load: ‐115.05
(+)Increment 73 : Strain: ‐0.08001 ‐ Displacement: ‐240.030 ‐ Axial Load: ‐115.61
(+)Increment 74 : Strain: ‐0.08112 ‐ Displacement: ‐243.363 ‐ Axial Load: ‐116.17
(+)Increment 75 : Strain: ‐0.08223 ‐ Displacement: ‐246.697 ‐ Axial Load: ‐116.73
(+)Increment 76 : Strain: ‐0.08334 ‐ Displacement: ‐250.030 ‐ Axial Load: ‐117.29

5. (+)Increment 77 : Strain: ‐0.08445 ‐ Displacement: ‐253.363 ‐ Axial Load: ‐117.85
(+)Increment 78 : Strain: ‐0.08557 ‐ Displacement: ‐256.697 ‐ Axial Load: ‐118.40
(+)Increment 79 : Strain: ‐0.08668 ‐ Displacement: ‐260.030 ‐ Axial Load: ‐118.96
(+)Increment 80 : Strain: ‐0.08779 ‐ Displacement: ‐263.363 ‐ Axial Load: ‐119.52
(+)Increment 81 : Strain: ‐0.08890 ‐ Displacement: ‐266.697 ‐ Axial Load: ‐120.08
Plot :