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Example 1 - rivt Doc | R Holland | v-1.0.0a12 | 2026-07-07 - 04:22AM
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0.1 | Summary and Loads
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This rivt file example calculates the maximum stress and deflection in a
simply supported, uniformly loaded beam using E-B theory [0.1.1]. It also
serves as an annotated example of a single rivt doc with multiple sections
that is not part of a report.
The example illustrates the use of some of the most common API functions,
commands and tags. Further details are provided in the
rivt user manual https://www.rivt.info .
The file may be formatted as a text, PDF or HTML doc by changing the type
parameter in the PUBLISH command at the end of each rivt file (Doc-API
rv.D). Published files are found in the _published folder.
0.1 - 2 | Load Combinations
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Dead and live loads effects are taken from ASCE 7-05 [0.1.2]
Table 1: Load Effects (stored: t001-1.csv)
============= ================================================
Equation No. Load Combination
============= ================================================
16-1 1.4(D+F)
16-2 1.2(D+F+T) + 1.6(L+H) + 0.5(Lr or S or R)
16-3 1.2(D+F+T) + 1.6(Lr or S or R) + (f1L or 0.8W)
============= ================================================
0.1 - 3 | Loads and Geometry
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Successive value definitions are formatted as a table. Variable values are
defined with the define operator. The line tag [T] labels and numbers the
table.
Table 2: Define Unit Loads
========== ============= ============= =====================
variable value [value] description
========== ============= ============= =====================
D_1 3.80 p_sf 0.18 kPA joists DL
D_2 2.10 p_sf 0.10 kPA plywood DL
D_3 10.00 p_sf 0.48 kPA partitions DL
D_4 3.00 k_ft 43.78 kN_m fixed machinery DL
L_1 40.00 p_sf 1.92 kPA ASCE7-O5 LL
b_1 10.00 inch 254.00 mm beam width
h_1 18.00 inch 457.20 mm beam depth
E_1 29000.00 k_si 199947.96 MPA modulus of elasticity
Fb_1 20000.00 p_si 137.90 MPA allowable stress
========== ============= ============= =====================
The VALTABLE command reads variable values from a file in the rvsrc/data
folder. The description is the table title, followed by the max
column width.
Table 3: Beam Geometry (rvsrc/data/beam1.csv)
========== ======== ========= =============
variable value [value] description
========== ======== ========= =============
spc_1 2.00 ft 0.61 m beam spacing
spn_1 16.00 ft 4.88 m beam span
========== ======== ========= =============
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Fig. 1 - Beam Diagram
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Uniform Distributed Loads
┌ Eq-1 | Dead load [ASCE7-05 2.3.2]
│
│ dl₁ = 1.2⋅(D₄ + spc₁⋅(D₁ + D₂ + D₃))
└
dl₁ = 3.64 k_ft [dl₁] = 53.09 kN_m | Dead load [ASCE7-05 2.3.2]
========= ========== ================== ============ =============
D₁ D₂ D₄ spc₁ D₃
========= ========== ================== ============ =============
3.80 p_sf 2.10 p_sf 3.00 k_ft 2.00 ft 10.00 p_sf
————— ————— ————— ————— —————
joists DL plywood DL fixed machinery DL beam spacing partitions DL
========= ========== ================== ============ =============
┌ Eq-2 | Live load [ASCE7-05 2.3.2]
│
│ ll₁ = 1.6⋅L₁⋅spc₁
└
ll₁ = 0.13 k_ft [ll₁] = 1.87 kN_m | Live load [ASCE7-05 2.3.2]
=========== ============
L₁ spc₁
=========== ============
40.00 p_sf 2.00 ft
————— —————
ASCE7-O5 LL beam spacing
=========== ============
┌ Eq-3 | Total load [ASCE7-05 2.3.2]
│
│ ω₁ = dl₁ + ll₁
└
ω₁ = 3.77 k_ft [ω₁] = 54.96 kN_m | Total load [ASCE7-05 2.3.2]
=================== ===================
dl₁ ll₁
=================== ===================
3.64 k_ft 128.00 ft·p_sf
————— —————
Dead load [ASCE7-05 Live load [ASCE7-05
2.3.2] 2.3.2]
=================== ===================
0.1 - 4 | Beam Response
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The following lines import the beam geometry from an external file,
calculate section properties from imported functions and calculate
the maximum moment, bending stress and mid-span deflection.
Table 4: (from file)
========================== ============================================
Function Docstring
========================== ============================================
rectsect(b, d) section modulus of rectangle
rectinertia(b, d) moment of inertia of rectangle
midspan_delta(ln, w, e, i) mid-span deflection of simply supported beam
with UDL
========================== ============================================
┌ Eq-4 | rectangle - S (sectprop.py)
│
│ section₁ = rectsect(b₁, h₁)
└
section₁ = 540.00 in3 [section₁] = 8849.01 cm3 | rectangle - S (sectprop.py)
========== ==========
b₁ h₁
========== ==========
10.00 inch 18.00 inch
————— —————
beam width beam depth
========== ==========
┌ Eq-5 | rectangle - I (sectprop.py)
│
│ inertia₁ = rectinertia(b₁, h₁)
└
inertia₁ = 4860.0 in4 [inertia₁] = 202288.5 cm4 | rectangle - I (sectprop.py)
========== ==========
b₁ h₁
========== ==========
10.0 inch 18.0 inch
————— —————
beam width beam depth
========== ==========
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Fig. 2 - Moment diagram | Fig. 3 - Deflection diagram
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Maximum bending stress formula
┌ Eq-6 |
│
│ M₁
│ σ₁ = ──
│ S₁
└
┌ Eq-7 | Mid-span UDL moment
│
│ 2
│ ω₁⋅spn₁
│ m₁ = ────────
│ 8
└
m₁ = 120.52 ft-kip [m₁] = 163.40 mkN | Mid-span UDL moment
==================== =========
ω₁ spn₁
==================== =========
3.77 k_ft 16.00 ft
————— —————
Total load [ASCE7-05 beam span
2.3.2] -
==================== =========
┌ Eq-8 | Bending stress
│
│ m₁
│ fb₁ = ────────
│ section₁
└
fb₁ = 2678.2 p_si [fb₁] = 18.5 MPA | Bending stress
=================== =============
m₁ section₁
=================== =============
120.5 ft2·k_ft 540.0 inch3
————— —————
Mid-span UDL moment rectangle - S
- (sectprop.py)
=================== =============
┌ Eq-9 | Stress ratio
│
│ fb_1 < Fb_1
└
▮ ========= ========== =============== ======= ============
▮ [1] fb₁ [2] Fb₁ ratio [1]/[2] check reference
▮ ========= ========== =============== ======= ============
▮ 2.68 k_si 20.00 k_si 0.13 OK Stress ratio
▮ ========= ========== =============== ======= ============
┌ Eq-10 | mid-span deflection (sectprop.py)
│
│ δ₁ = midspan_δ(spn₁, ω₁, E₁, inertia₁)
└
δ₁ = 0.04 inch [δ₁] = 1.00 mm | mid-span deflection (sectprop.py)
============= ==================== ============= =========
inertia₁ ω₁ E₁ spn₁
============= ==================== ============= =========
4860.00 inch4 3.77 k_ft 29000.00 k_si 16.00 ft
————— ————— ————— —————
rectangle - I Total load [ASCE7-05 modulus of beam span
(sectprop.py) 2.3.2] elasticity -
============= ==================== ============= =========
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[0.1.1] "Euler–Bernoulli beam theory", Wikipedia, Wikimedia Foundation.
[Online].https://en.wikipedia.org/wiki/Euler_Bernoulli_beam_theory.[Accessed:
Jun. 15, 2026].
[0.1.2] ASCE/SEI 7-05, Minimum Design Loads for Buildings and Other
Structures,American Society of Civil Engineers, 2005.
