Design checks

Design checks

extensions/design/ checks building members and foundations by the US design codes. Steel beams, columns and connections follow AISC 360-16 (ASD). Sawn lumber and bolts follow the NDS 2018. Concrete walls, footings and anchors follow ACI 318-19. Wind pressure follows ASCE/SEI 7.

Continuous beams use the solver of Frame analysis. The module also writes the values and the TikZ drawing bodies of a LaTeX calculation package. It builds staged 3D views of a structure, colored by demand-to-capacity ratio.

The checks take and return unit-typed quantities. Inside, they work in the units of the code: pounds, kips, inches and feet.

Modules

Module	What it gives
quantities	POUND64, PSI, KIP_INCH, KIP_FOOT, POUND_FOOT, SQUARE_INCH, CUBIC_INCH, INCH_TO_THE_FOURTH, MILE_PER_HOUR and POUND_PER_INCH. extensions.geotech.quantities gives PSF, PLF, KIP, KSI and PCF
kinds	WindExposure (EXPOSURE_B, EXPOSURE_C, EXPOSURE_D) and AnchorKind (CAST_IN, POST_INSTALLED)
steel	WideFlange, w_shapes and w_shape (W8 to W12), flexural_strength (F2, F3), shear_strength (G2.1), web_local_yielding (J10.2), web_crippling (J10.3), Pipe and standard_pipes, compression_strength (E3), concrete_bearing (J8), WideFlange.strong_radius, combined_ratio (H1.1), fillet_weld_strength (J2.4), bolt_shear_strength (J3.6), base_plate_thickness (Design Guide 1) and the ASD safety factors
wood	Lumber, southern_pine_no2, dressed_depth, joist_line_load, simple_span_check, bearing_stress_ratio, dowel_bearing_strength and bolt_lateral_value (the yield limit equations)
concrete	propped_wall_effects, cantilever_wall_effects, stress_block_factor, tension_strain, one_way_shear_strength, two_way_shear_stress, plain_flexural_strength, minimum_wall_steel, wall_in_plane_shear_strength, plain_bearing_strength, plain_two_way_shear_strength, square_footing_side and strip_footing_width
anchors	One anchor by ACI 318-19 chapter 17: steel_tension_strength, steel_shear_strength, breakout_tension_strength, pullout_strength, bond_tension_strength, pryout_shear_strength, concrete_tension_phi and the steel and pryout factors
wind	exposure_coefficient (Kz), elevation_factor (Ke), velocity_pressure (qz), leeward_wall_coefficient and wall_net_pressure
beams	continuous_beam and patterned_beam
latex	TexValues, group_thousands, fixed and feet_inches
tikz	TikzBody, the commands of a drawing in model units
assembly	Part, Assembly, add_assembly, ratio_color, draw_ratio_legend and orbit_eye

Check a member

Each check returns the nominal strength, or the stresses and their ratios. Divide a nominal strength by the safety factor that the module exports.

from extensions.design.steel import flexural_strength, w_shape
from extensions.design.quantities import KIP_FOOT
from extensions.geotech.quantities import KSI
from units.si import INCH64, Length64, Pressure64

def main() raises:
    var f = flexural_strength(
        w_shape("W8x18"), Pressure64(50, KSI), Length64(16, INCH64), 1.0
    )
    print(f.allowable().to(KIP_FOOT))  # 42.4, as AISC Manual Table 3-2

Analyze a basement wall

A basement wall spans from the slab at its base to the floor at its top. propped_wall_effects takes the span, the height of the soil above the bottom support, the equivalent fluid pressure and a uniform lateral surcharge. It integrates the pressure for the reactions and scans the moment along the span. Soil above the top support loads the wall only up to the span.

Give the result to flexural_resistance and shear_resistance of extensions.geotech.concrete, or to one_way_shear_strength here, with the load factor of your code.

Check an anchor

The functions of anchors give the nominal strength of one anchor. Multiply each by its phi. Give the four edge distances of the anchor. Give 1.5 h_ef or more for a side without an edge.

1. Get the steel strength with steel_tension_strength or steel_shear_strength.
2. Get the concrete breakout with breakout_tension_strength. Near three or four edges, the function reduces h_ef as 17.6.2.1.2 tells.
3. For a headed anchor, get pullout_strength. For an adhesive anchor, get bond_tension_strength with the bond stresses of the product's evaluation report.
4. For shear, get pryout_shear_strength from the least concrete tension strength.
5. Use the least value. The concrete is taken as cracked, which is conservative.

Analyze a continuous beam

continuous_beam puts one support at each end of each span and loads each span with its own uniform load. patterned_beam puts the dead load on every span and the live load on each of the 2^n patterns of spans. It keeps the worst value of each effect. The moments come from the reactions by statics, so they do not depend on the stiffness. The deflections use E I.

Write a calculation package

A drawing set and its report quote the same numbers. Collect each number once in a TexValues, write it, and \input the file in both documents. A TikzBody writes a plan or a section in model units. The sheet sets the scale with the x and y keys of its tikzpicture. The style names, such as wl and concfill, and the \dimline and \dimlinev macros come from the sheet's preamble.

Animate a structure

Put each member in an Assembly as a Part, with its construction stage and its ratio. Call add_assembly for each frame:

• A build from 0 to the stage count shows the construction sequence. Parts of the current stage come down into place.
• by_ratio colors each rated part with utilization_color. draw_ratio_legend paints the scale into the frame.
• first_stage leaves out early stages, such as the ground.

orbit_eye turns the camera around the model. The y axis is up.

Limits

• The steel catalog holds the light W8, W10 and W12 shapes and three standard pipes. Add rows for other shapes.
• flexural_strength assumes a compact web. Every catalog W shape has one for Fy up to 65 ksi.
• southern_pine_no2 holds 2-inch Southern Pine No. 2 only. Other species and grades need their own Lumber.
• anchors checks one anchor. A group of anchors, shear breakout toward an edge and supplementary reinforcement are not covered.
• The wind functions cover the main wind force resisting system of a rigid low building. Components and cladding are not covered.
• These are checks, not a design code. An engineer must choose the loads, the combinations and the limits.