Example engineering report.

Figures are generated live from the inputs listed above. Geometry is drawn to scale within each viewBox; absolute sizes are illustrative only. Use the figures as a qualitative check that geometry and loading are not obviously wrong — they are not a CAD drawing.

• Geometry is a single-plate lug / padeye without cheek plates. Cheek-plate configurations are out of scope for v1 and require detailed analysis.
• Load is applied in the plane of the lug. Out-of-plane bending from sling misalignment is treated via a user-supplied dynamic / skew factor only.
• Behaviour assumed linear-elastic, isotropic, homogeneous. No plastic redistribution, residual stresses, or fatigue effects are considered.
• Load line passes through the hole centre. Eccentricities between sling and lug centreline are not explicitly evaluated.
• Allowable stresses are supplied by the user. The app does NOT apply any code-specific allowable factor (ASME BTH-1 $0.45F_y$, Eurocode ${\gamma }_M$, DNV DAF, etc.) until the corresponding source clause has been supplied and validated.
• Pin-to-hole fit is assumed reasonable (pin diameter slightly less than hole diameter). Extreme clearances or wear are not modelled.
• Bearing stress is taken as the projected nominal value ${\sigma }_b=\frac{F}{d_{p}t}$; actual contact stress peaks are not resolved.
• Fillet welds are symmetric about the load line. The weld group is analysed with $N=F\cos \theta$, $V=F\sin \theta$, $M=V\cdot h$ (in-plane bending). Root components $f_z=N/A_w+M/S_w$ and $f_v=V/A_w$ are transformed to throat stresses ${\sigma }_{\perp }={\tau }_{\perp }=f_z/\sqrt{2}$ and ${\tau }_{\parallel }=f_v$. Out-of-plane (sling skew) effects and asymmetric weld runs remain out of scope in v1.

• MECH_NET_SECTIONMechanics of Materials — net-section tension
  Average tensile stress on the net cross-section through the pin hole: $\sigma =\frac{F}{(w-d)t}$. Classical identity; no code-specific allowable applied.
• MECH_DOUBLE_SHEAR_OUTMechanics of Materials — double-plane shear-out
  Average shear stress on two tear-out planes between hole and free edge: $\tau =\frac{F}{2L_{s}t}$, where $L_s=a-\frac{d}{2}$. Classical identity; no code-specific allowable applied.
• MECH_BEARINGMechanics of Materials — bearing stress
  Nominal bearing stress on the projected pin-on-plate area: ${\sigma }_b=\frac{F}{d_{p}t}$. Classical identity; no code-specific allowable applied.
• MECH_PIN_SHEARMechanics of Materials — pin double shear
  Average shear stress on two pin cross-sections (single-lug in clevis): $\tau =\frac{F}{2A_{\text{pin}}}$. Classical identity; no code-specific allowable applied.
• MECH_FILLET_WELD_THROATMechanics of Materials — fillet weld throat resultant
  Resultant throat stress on a fillet weld group with angle-aware demand decomposition $N=F\cos \theta$, $V=F\sin \theta$, $M=V\cdot h$. Root components $f_z=\frac{N}{A_w}+\frac{M}{S_w}$ and $f_v=\frac{V}{A_w}$ give throat components ${\sigma }_{\perp }={\tau }_{\perp }=f_z/\sqrt{2}$ and ${\tau }_{\parallel }=f_v$; $|R|=\sqrt{f_z^2+f_v^2}$ is compared to the user-supplied shear allowable. No ${\gamma }_M$ or electrode-specific factor applied.
• MECH_FILLET_WELD_VMMechanics of Materials — von Mises throat stress
  Combined throat stress for a fillet weld group using the von Mises equivalent ${\sigma }_{\mathrm{eq}}=\sqrt{{\sigma }_{\perp }^2+3({\tau }_{\perp }^2+{\tau }_{\parallel }^2)}$, compared to the user-supplied tensile allowable (falls back to ${\tau }_{\text{allow}}\sqrt{3}$).
• AISC_WELD_J24AISC 360-22 §J2.4 · 2022 · §J2.4, Eq. J2-5 (directional strength increase)
  Nominal fillet-weld strength per unit throat area $F_{nw}=0.60F_{EXX}(1.0+0.5{\sin }^{1.5}\theta )$, where $\theta$ is the angle between the line of action of the force resultant and the weld longitudinal axis. ASD safety factor $\Omega =2.0$ per §B3.2.
• BTH1_NET_TENSIONASME BTH-1-2020 §3-3.3.1 · 2020 · §3-3.3.1 (eqs 3-45 through 3-48)
  Static strength of pin-connected plate — tension on the effective net area either side of the pin hole, with $C_r$ reduction for pin/hole clearance and $b_{\mathrm{eff}}=\min \left(4t,0.6b_e\sqrt{\frac{F_u{D}_h}{F_y{b}_e}}\right)$. Allowable includes design factor $N_d$ per §3-1.3.
• BTH1_DESIGN_FACTORASME BTH-1-2020 §3-1.3 · 2020 · §3-1.3
  Design factor $N_d$: $2.00$ for Design Category A, $3.00$ for Design Category B. Applied to all §3-3 allowables.
• BTH1_FRACTUREASME BTH-1-2020 §3-3.3.2 · 2020 · §3-3.3.2 (eq 3-49)
  Single-plane fracture strength of the plate beyond the pin hole.
• BTH1_SHEAR_OUTASME BTH-1-2020 §3-3.3.3 · 2020 · §3-3.3.3 (eqs 3-50 through 3-52)
  Double-plane shear-out strength: $A_v=2t[a+\frac{D_p}{2}(1-\cos \phi )]$, with $\phi =55^{\circ }\frac{D_p}{D_h}$ and allowable $P_v=\frac{0.70F_u{A}_v}{1.20N_d}$.
• BTH1_BEARINGASME BTH-1-2020 §3-3.3.4 · 2020 · §3-3.3.4 (eqs 3-53 / 3-54)
  Pin bearing strength on the lug plate. Static bearing allowable $\frac{1.25F_y}{N_d}$; rotating (Service Class $\ge 1$) reduced to $\frac{0.63F_y}{N_d}$.
• BTH1_WELDASME BTH-1-2020 §3-3.4.3 · 2020 · §3-3.4.3 (eq 3-55)
  Allowable fillet-weld shear on the effective throat $F_v=\frac{0.60F_{EXX}}{1.20N_d}$. Extended to combined in-plane loading by comparing the resultant throat stress $f_{\mathrm{res}}=\sqrt{f_z^2+f_v^2}$ against the clause allowable.
• EC3_PIN_GEOMETRYEN 1993-1-8:2005 §3.13.1 · 2005 · §3.13.1, Table 3.9
  Geometric requirements for pin-connected plates: minimum plate thickness, minimum distances $a$ and $c$ from hole centre to plate edges as functions of $F_y$, ${\gamma }_{M0}$, and $d_0$.
• EC3_PIN_SHEAREN 1993-1-8:2005 §3.13.2 · 2005 · §3.13.2, Table 3.10 (shear)
  Pin shear resistance per plane: $F_{v,\mathrm{Rd}}=\frac{0.6A{f}_{up}}{{\gamma }_{M2}}$. A single-lug / clevis assembly presents two shear planes.
• EC3_PLATE_BEARINGEN 1993-1-8:2005 §3.13.2 · 2005 · §3.13.2, Table 3.10 (bearing)
  Pin/plate bearing resistance: $F_{b,\mathrm{Rd}}=\frac{1.5td{f}_y}{{\gamma }_{M0}}$.
• EC3_PIN_BENDINGEN 1993-1-8:2005 §3.13.2 · 2005 · §3.13.2, Table 3.10 & Figure 3.11 (bending)
  Pin bending resistance: $M_{\mathrm{Rd}}=\frac{1.5W_{\mathrm{el}}{f}_{yp}}{{\gamma }_{M0}}$ with $W_{\mathrm{el}}=\frac{\pi d^3}{32}$. The demand $M_{\mathrm{Ed}}$ follows Figure 3.11: $M_{\mathrm{Ed}}=\frac{F_{\mathrm{Ed}}}{8}(b+4c+2a)$; evaluated when the user supplies the shackle fork geometry (jaw thickness $a$ and either inside-jaw width $W$ or clearance $c$).
• EC3_PIN_COMBINEDEN 1993-1-8:2005 §3.13.2 · 2005 · §3.13.2, Table 3.10 & Figure 3.11 (combined)
  Combined shear + bending interaction on the pin: ${\left(\frac{M_{\mathrm{Ed}}}{M_{\mathrm{Rd}}}\right)}^2+{\left(\frac{V_{\mathrm{Ed}}}{F_{v,\mathrm{Rd}}}\right)}^2\le 1$. Gated on the same shackle fork geometry as the pin-bending check.
• EC3_WELD_DIRECTIONALEN 1993-1-8:2005 §4.5.3.2 · 2005 · §4.5.3.2 (directional method)
  Directional check for a fillet weld throat. Two criteria: $\sqrt{{\sigma }_{\perp }^2+3({\tau }_{\perp }^2+{\tau }_{\parallel }^2)}\le \frac{f_u}{{\beta }_w{\gamma }_{M2}}$ and ${\sigma }_{\perp }\le \frac{0.9f_u}{{\gamma }_{M2}}$. Correlation factor ${\beta }_w$ taken from Table 4.1 based on the weaker joined steel grade.
• EC3_WELD_SIMPLIFIEDEN 1993-1-8:2005 §4.5.3.3 · 2005 · §4.5.3.3 (simplified method)
  Simplified check on the weld throat as a vector shear: $F_{w,Ed}\le F_{w,Rd}=f_{vw,d}a$ with $f_{vw,d}=\frac{f_u/\sqrt{3}}{{\beta }_w{\gamma }_{M2}}$. Conservative relative to the directional method; shown as a cross-check.
• DNV_N001_DAFDNV-ST-N001 §16 · 2020-01 · Section 16 (lifting)
  Dynamic amplification factor applied to the static rigging load. Values depend on lift weight and environment category (onshore light / standard / heavy; offshore sheltered / open sea). Defaults below are starting values — user must confirm against the project-specific clause.
• DNV_N001_SKEWDNV-ST-N001 §16 · 2020-01 · Section 16 (lifting)
  Skew-load factor for multi-sling lifts. Single-lug padeyes receive only the SKL multiplier on the sling force; governing SKL redistribution applies to multi-point rigging.