What's New
What's New in the Unified Fracture Mechanics Tool
Version 5.9.4 — a summary of what has changed since Version 5.7.
Version 5.7 already covered LEFM, fatigue, variable‑amplitude loading, stress fields, EPFM, a materials library, subcritical crack growth for glass, and a Learning Center. The releases since then have deepened the physics, opened the tool up to metals, made every material parameter visible in one place, added full control over the program's appearance, and moved distribution to a single, self‑contained Windows executable. Here is the short version.
By the numbers
Tabs: 9 → 10 (a new Tools tab).
Materials: 91 → 103, across 13 → 14 categories.
Learning Center lessons: 16 → 17.
Verification checks: 65 → 76, all passing.
1. Subcritical crack growth grew up — a trilinear law, environments, and metals
This is the biggest change. In v5.7, subcritical crack growth used a single Region‑I power law (v = A·Kⁿ) and applied only to glass and ceramics; the manual listed "Region I only — no transport‑limited plateau, no explicit humidity model" as a known limitation. That limitation is now resolved.
A trilinear v–K model. Growth now follows Region I (the power law), a near‑constant Region‑II plateau, and a steep Region‑III rise toward K_IC — the shape real stress‑corrosion data actually takes.
Selectable environments. A new Environment control scales the kinetics: Water, Humid Air (50% RH), Dry Air, and Vacuum. Water accelerates growth; dry air and vacuum nearly stop it.
Stress‑corrosion cracking of metals. A new Metal SCC category adds 10 measured material‑environment systems spanning the four classic mechanisms — anodic dissolution (7075‑T651 / 7075‑T7351 / 2024‑T351 in salt water, brass in ammonia), hydrogen embrittlement (AISI 4340, 300M), chloride SCC (304 stainless, Ti‑6Al‑4V), and high‑temperature water (Inconel 600 PWSCC). Loading a measured system switches the model to Trilinear automatically and marks the parameters as measured.
The practical payoff is two design levers you can now demonstrate directly: the steep σ⁻ⁿ stress sensitivity for glass, and the temper/environment sensitivity for metals — for example, moving 7075 from its peak‑aged temper (K_ISCC ≈ 7) to its resistant temper (K_ISCC ≈ 20) can drop the same crack below threshold so it never grows.
2. A new Tools tab — theme, colors, and fonts
v5.7 had no appearance controls. The new Tools tab lets you restyle the whole program without touching a calculation.
Theme presets — Light, Dark, Slate, Sepia, and High Contrast — plus individual pickers for the accent, window, panel, text, and field colors.
Fonts — choose the family and size, with a live preview.
Font‑safe scaling. Enlarging the font now re‑scales the window to fit and adds a scrollbar to dense control columns only when needed, so a larger font never hides a button. Plot interiors stay light in every theme so curves and labels remain legible.
Persistence. Save your choice as the default and it is re‑applied on the next launch; on first run the native look is left untouched.
3. The Materials Library is bigger — and fully transparent
The library grew from 91 to 103 materials and from 13 to 14 categories (the new Metal SCC category, plus additions to the ceramics and display‑glass sets). More importantly, every parameter the program uses is now visible in one place.
New columns for Poisson's ratio (ν) and density (ρ), so they are visible at a glance rather than buried in the details pane.
A complete details pane. Selecting a material now shows the full parameter set: the standard properties and derived quantities as before, plus the EPFM Ramberg‑Osgood hardening exponent used on the J‑Integral tab and — for materials that carry measured environmental data — the SCCG constants (the exponent n, the threshold K_ISCC, and the Region‑II plateau velocity). Nothing the tool relies on is hidden on another tab anymore.
4. Learning Center — a new lesson
The course grew from 16 to 17 lessons. The new lesson, "Stress‑Corrosion Cracking of Metals," teaches the plateau‑dominated behavior and the temper/environment levers, and its "Try It Live" button loads a real metal‑SCC case (7075‑T651 in salt water) and runs it.
5. Verification — 65 to 76 checks
The verification suite expanded to cover the new physics: the SCCG bridge from measured constants, the trilinear plateau and Region‑III rise, environment scaling, all 10 metal‑SCC systems (silent below K_ISCC, on‑plateau above), the temper lever, and the new library columns. The headless GUI smoke test now also exercises the Tools tab — applying a theme, changing the font, and confirming the window re‑scales. Every released build is verified before it ships.
6. Now shipped as a single Windows executable
v5.7 ran from Python (install the packages, then run the scripts). The tool now ships as one self‑contained Windows executable — no Python, no packages, no dependencies, and no administrator rights. Copy it to any folder and double‑click; it is fully portable and writes nothing outside the application. The window title bar and Help ▸ About show the exact build so you can confirm you are on the current release.
Unified Fracture Mechanics Tool v5.9.4 · Joseph P. McFadden Sr. · www.mcfaddencae.com. Library values are representative screening data for education and preliminary analysis — not certified design allowables.
