Strength Analysis of a Rectangular Beam
Objective: Check the mode for calculating reinforced concrete structures in the “Reinforced Concrete” postprocessor of SCAD
Task: Check the strength of the cantilever beam section for the specified reinforcement
References: Guide on designing of concrete and reinforced concrete structures made of heavy-weight or lightweight concrete (no prestressing) (to SNiP 2.03.01-84), 1989, p. 26.
Initial data file:
SCAD 3 SNiP.spr
report – SCAD 3 SNiP.doc
Compliance with the codes: SNiP 2.03.01-84.
Initial data:
| b = 200 mm | Beam section sizes |
| h = 800 mm | |
| а = 50 mm | Distance from the center of gravity of the reinforcement to the compressed edge of the section |
| As = 2945 mm2 (6Ø25) | Cross-sectional area of reinforcement |
| Concrete class | В25 |
| Class of reinforcement | А-III |
| l = 4,8 m | Beam span |
| q = 191 kN/m | Load on the beam |
| М = 550 kN/m | Bending moment in the section under the load |
Results of the SCAD analysis:
|
N Max. 0 T
Max. 0 T |
My Max. 0 kN*m
Max. 550,55 kN*m |
Mz
|
|
Mk
|
Qz
Max. -11,21 T |
Qy
|
|
|
Length of the bar 5 m |
|
Structural group Beam
Distance between the rebars in the first row S1 is less than the allowable value (see Sec. 5.12 of SNiP 2.03.01-84*) .
Elements: 1
Importance factor γn = 1
Importance factor (serviceability limit state) = 1
Member type – Flexural
Stress state - Uniaxial bending
|
Coefficients allowing for seismic action |
||
|---|---|---|
|
Normal sections |
0 |
|
|
Oblique sections |
0 |
|
|
Distance to the c.o.g. of reinforcement |
|
|---|---|
|
a1 |
a2 |
|
mm |
mm |
|
50 |
50 |
|
Reinforcement |
Class |
Service factor |
|---|---|---|
|
Longitudinal |
A-III |
1 |
|
Transverse |
A-I |
1 |
Concrete
Concrete type: Heavy-weight
Concrete class: B25
Hardening conditions: Natural
Hardening factor 1
|
Service factor for concrete |
||
|---|---|---|
|
γb2 |
allowance for the sustained loads |
0,9 |
|
|
resulting factor without γb2 |
1 |
Humidity of environmental air - 40-75%
Crack resistance
Category of crack resistance - 3
Conditions of operation: Indoors
Mode of concrete humidity - Natural humidity
Allowable crack opening width:
Short-term opening 0,4 mm
Long-term opening 0,3 mm
Structural group Beam. Element No. 1
Member length 5,0 m
Specified reinforcement
|
Segment |
Reinforcement |
Section |
|
1 |
S1 - 6Ø25
|
|
|
Results |
|||
|---|---|---|---|
|
Segment |
Utilization factor |
Check |
Checked according to SNiP |
|
1 |
0,83 |
Ultimate moment strength of the section |
Sec. 3.15-3.20, 3.27-3.28 |
Comparison of solutions
|
Check |
strength of the section |
|
Guide |
550/636,4 = 0,864 |
|
SCAD |
0,83 |
|
Deviation, % |
4,1 % |