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Input glossary

Reference

Every input box of every module, with its symbol, units and what it does. Percent strains are entered as percent; the compression ultimate strain is entered as a fraction of 1.

Geometry (all modules)

Input Symbol SI US Notes
Span (L) \(L\) mm in Clear span between supports
Width (b) \(b\) mm in Section width
Height (h) \(h\) mm in Section depth. In the EN 14651 module it is the ligament depth above the notch, 125 mm for the standard prism
Plastic Length (Lp) \(L_p\) mm in Localization length. Suggested: \(S_2\) in 4-point bending, \(h\) in 3-point bending, 25 mm for the EN 14651 prism
Loc. Length (Lp2) \(L_{p2}\) mm in TRC module only, the post-peak localization zone
Notch Depth \(d_n\) mm in EN 14651 module only. The distance from the notch tip down to the CMOD gauge line. Added below the height in the drawings; the total prism depth is \(h + d_n\)
Loading (3 or 4) 3-point or 4-point bending
Load Spacing (4pb) \(S_2\) mm in Distance between the two loads in 4-point bending
Concrete Cover \(c\) mm in Design modules, cover to the bar center
Top / Bot. Rebar Dia, Count mm, count in, count Design modules, a count of 0 removes the layer
# of Textile count count TRC module, textile layers through the thickness

Tension model

Input Symbol SI US Notes
Elastic Modulus (E) \(E\) MPa psi Tensile modulus of the matrix
Cracking Strain \(\varepsilon_{cr}\) % % Cracking stress is \(E\,\varepsilon_{cr}\)
Stress Coordinate 1, 2, 3 \(\sigma_1, \sigma_2, \sigma_3\) MPa psi Post-cracking stresses
Strain Coordinate 1, 2, 3 \(\varepsilon_1, \varepsilon_2, \varepsilon_3\) % % Strains at the stresses above, increasing
Crack Width 1, 2, 3 \(w_1, w_2, w_3\) mm in EN 14651 module, in place of the strain coordinates. The model's internal crack opening, not the measured CMOD

Crack-opening coordinates of the notched-beam module

Version note. This separation of measured CMOD, model CMOD and model CTOD, and the Load-CMOD tab name, belong to the EN 14651 change listed under Unreleased in the release notes. Earlier builds name that tab Load-Crack Width. The symbols and the kinematics themselves are unchanged.

Term Symbol Meaning
Measured CMOD \(\text{CMOD}_{exp}\) Crack-mouth opening recorded by the clip gauge. The fixed experimental x coordinate, used exactly as imported
Model CMOD \(\text{CMOD}_{sim}\) Crack-mouth opening the current model predicts, \(\text{CTOD}_{total}\left[1 + d_n/((1-k)h)\right]\). The x axis of the Load-CMOD tab
Model CTOD \(\text{CTOD}_{total}\) Opening at the notch tip, \(w + \varepsilon_{cr} L_p\). The x axis of the Moment-Crack Width, Flexural Stress-Crack Width and Stress Profile tabs
Crack opening \(w\) Post-cracking excess opening of the tension law, the coordinate of \(w_1, w_2, w_3\)
Notch depth \(d_n\) Notch tip down to the CMOD gauge line
Ligament depth \(h\) Depth above the notch tip, the Height input. Not the total specimen depth

Suggested values printed on the tab, ACI 318-19 normalweight concrete: \(E_c = 4700\sqrt{f'_c}\) MPa, \(f_r = 0.62\sqrt{f'_c}\) MPa, \(\varepsilon_{cr} = f_r/E_c\). In US units \(E_c = 57000\sqrt{f'_c}\) psi and \(f_r = 7.5\sqrt{f'_c}\) psi.

Compression model

Input Symbol SI US Notes
Elastic Modulus (Ec) \(E_c\) MPa psi Compressive modulus
Yield Strength (f'c) \(f'_c\) MPa psi Compressive strength, reached at \(f'_c/E_c\)
Residual Stress (f'cu) \(f'_{cu}\) MPa psi Stress at the maximum strain. Equal to \(f'_c\) for a plastic plateau. Not present in the EN 14651 module, whose law is flat after the strength
Max. Strain Limit, Ultimate Strain \(\varepsilon_{cu}\) fraction or % fraction or % A fraction of 1 in the ASTM C1609, Hybrid and FRP modules (0.0125), percent in the EN 14651 and TRC modules (1.25). The unit is printed beside the box

Reinforcement model (Hybrid beam, Cross-sectional)

Input Symbol SI US Notes
Elastic Modulus (Es) \(E_s\) MPa psi
Yield Strength (fsy) \(f_{sy}\) MPa psi
Ultimate Stress (fsu) \(f_{su}\) MPa psi Equal to \(f_{sy}\) for no hardening
Ultimate Strain \(\varepsilon_{su}\) fraction fraction Rupture strain

Non-metallic bars and laminate (FRP module)

Input Symbol SI US Notes
Bar Modulus (Ef) \(E_f\) MPa psi Linear to rupture
Tensile Strength (ffu) \(f_{fu}\) MPa psi Rupture strain is \(f_{fu}/E_f\)
Laminate Width (bf) \(b_f\) mm in
Thickness per Ply (tf), Number of Plies \(t_f, n\) mm in Laminate area is \(b_f\, n\, t_f\)
Laminate Modulus, Tensile Strength \(E_f, f_{fu}\) MPa psi
Substrate Strain at Bonding % % Soffit strain present when the laminate was applied
Debonding Strain Limit \(\varepsilon_{fd}\) % % 0 lets rupture govern
Once the Laminate is Lost Stop the analysis, or continue without the laminate

Cross-sectional module

Input SI US Notes
Preset Shape, Preset Parameters in in Published AASHTO and PCI dimensions, always in inches
Section Vertices, Void mm in Outline and void as x, y pairs
Axial Load (P) N lbf Compression positive
Mesh layers, Curvature steps, P-M axial points Discretization. Defaults 240, 500, 25
Transverse Tied (φ 0.65, 0.80 cap) or Spiral (φ 0.75, 0.85 cap), ACI 318-19
Tension levels Axial levels added below zero for the P-M diagram
Rebar Layers: y, As, x mm, mm² in, in² Height from the bottom, layer area, drawing position
Tendons: Ep, fpy, fpu, εpu, Ap MPa, mm² psi, in² Strand law and area of one strand
Tendon Layers: y, strands, fpe mm, MPa in, psi Height, number of strands, effective prestress after losses
Test, Span L, Load spacing S2, Localization length Lp mm in Load-Deflection tab