FRAME-LINK — Fatigue Reliability Dashboard for Structural Connections

Connection Structural Integrity Index

—

CSII

—

LOADING…

CSII = 0.40·(1−S_deg) + 0.35·(1−D/D_allow)
+ 0.25·(β/β_target)
Accuracy ±2.93% · Forecast 24–48h

Safety Bounds — Real-Time

Reliability β

—

≥ 3.80 target

Fatigue D_joint

— M

< 0.80 limit

Stiffness S_deg

— %

< 10% warning

Crack Depth a

— mm

< 0.6·a_cr

Module Outputs — Current Cycle

da/dN ×10⁻⁹

— m/cyc

Paris law

ΔK SIF

— MPa√m

K_Ic bound

A_score Anomaly

—

> 3σ threshold

LSTM +48h

—

AISL forecast

Welded T-Joint — Strain Field & Crack Growth

━ Weld toe ━ Crack propagation IIW 0.4t / 1.0t

Paris–Erdogan — da/dN vs ΔK

da/dN (crack rate)—

ΔK (SIF)—

Stiffness K_joint—

Three-Module Assessment Pipeline — SCFMM · FDARM · CSDM

SCFMM

Stress Concentration
& Fracture Mechanics

—

da/dN

—

ΔK

—

a_crack

—

FDARM

Fatigue Damage
& Reliability Module

—

D_joint

—

β index

—

FAT class

FAT71

CSDM

Connection Stiffness
Degradation Module

—

S_deg

—

K/K₀

—

AI assist

XGB+LSTM

CSII — 72-Hour History & 48-Hour AISL Forecast

SCFMM + FDARM + CSDM composite · Physics-constrained LSTM projection

Fatigue Damage Map — D(x,t)

30 instrumented connection details · Palmgren–Miner · IIW hot-spot · FAT71

D<0.30 0.30–0.60 >0.60 Goodman corr.

48h AISL Trajectory Forecast

XGBoost anomaly + physics-constrained LSTM · ±σ band

T+0hT+12hT+24hT+36hT+48h

Governing Equations

FRAME-LINK v1.0.0 analytical core

Eq. 1 — Paris–Erdogan

da/dN = C·(ΔK)^m

Eq. 2 — Stress Intensity Factor

ΔK = Y·Δσ·√(π·a)

Eq. 3 — Palmgren–Miner

D_joint = Σ n_i/N_i(Δσ_i)

Eq. 4 — Cornell Reliability

β = (μ_R - μ_S)/√(σ_R² + σ_S² + σ_AI²)

Eq. 5 — Stiffness Degradation

S_deg = 1 - K_joint/K_joint,0

Eq. 6 — Connection Integrity Index

CSII = 0.40·(1-S_deg) + 0.35·(1-D/D_allow) + 0.25·(β/β_target)

Safety Bounds & Governance Thresholds

CONN-SAFETY-01 · v1.0.0 certification bounds

Parameter	Current	Bound	Status
CSII	—	≥ 0.90	Steady
β index	—	≥ 3.80	OK
D_fatigue	—	< 0.80	OK
S_deg	—	< 0.10	OK
Crack depth a	—	< 0.6·a_cr	OK
da/dN	—	—	Monitored
A_score	—	< 3σ	Watch

Validation v1.0.0

CSII Accuracy±2.93% Crack Rate Error4.1% Fatigue MAE3.3% β Accuracy±4.3%