# PlexiSafe

> PlexiSafe (iPhone/iPad app by Valerie Otero.)

- Source: https://appshunter.io/ios/app/plexisafe/id6761058642 (this page in markdown: same URL + `.md`)
- Developer: [Valerie Otero](https://appshunter.io/developer/1848585337)
- Category: Utilities
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 26.2 · 6 MB
- Languages: English
- Released: 2026-03-25
- Data updated: 2026-07-08
- User reviews in markdown: https://appshunter.io/ios/app/plexisafe/id6761058642/reviews.md

## What is PlexiSafe?

Cracked acrylic or polycarbonate panel? PlexiSafe tells you exactly where to drill and what diameter to use to stop the crack from spreading before it is too late.

Based on Linear Elastic Fracture Mechanics (LEFM), PlexiSafe calculates the minimum stop-drill hole diameter, evaluates stresses, and gives you an instant verdict: repair safe, warning, or critical.

--- WHAT PLEXISAFE CALCULATES ---

- Minimum stop-drill hole diameter (d_min)
- Stress intensity factor K_I
- Critical crack length before fracture
- Net stress and stress concentration at the hole
- Structural verdict: safe repair, warning, or critical

--- HOW TO USE PLEXISAFE ---

1. Enter your plate dimensions: width, thickness, span
2. Enter the crack position and measured deflection
3. Choose your material (Standard PMMA, Reinforced PMMA, or Polycarbonate)
4. Tap Calculate: PlexiSafe shows the drill hole diameter and the verdict

--- FEATURES ---

- 3 material presets: Standard PMMA, Reinforced PMMA, Polycarbonate
- Customizable parameters: allowable stress, fracture toughness K_IC, factor Y
- 3 unit systems: mm/MPa, m/MPa, m/kPa
- Color-coded verdict (green / orange / red)
- Detailed safety margins and inspection recommendation
- Full history: name and archive every calculation
- Report export (email, AirDrop, print)
- 100% offline — no data transmitted, no account required
- Available in French, English, Spanish, Portuguese and Chinese

--- FORMULA ---

K_I = Y x sigma x sqrt(pi x a)
Fracture when K_I >= K_IC
d_min = 2 x (x + delta)

--- PRIVACY ---

PlexiSafe collects no personal data. Everything is stored locally on your device.

--- DISCLAIMER ---

PlexiSafe is a calculation aid tool. Results are indicative and do not replace the advice of a qualified engineer.

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Small coffee | $1.99 | one-time |
| Medium coffee | $3.99 | one-time |
| Large coffee | $5.99 | one-time |



## Version history (last 1 release)

### 1.0 — 2026-03-25

No release notes.

## More apps by Valerie Otero

- [AirMultiChrono](https://appshunter.io/ios/app/airmultichrono/id6754513036)
- [SkyNotes](https://appshunter.io/ios/app/skynotes/id6755604004)
- [QuantumPass](https://appshunter.io/ios/app/quantumpass/id6755789663)
- [METAR•TAF Flow](https://appshunter.io/ios/app/metartaf-flow/id6757341500)
- [Theta Resonance](https://appshunter.io/ios/app/theta-resonance/id6761909162)

All apps by Valerie Otero: https://appshunter.io/developer/1848585337

## Related topics

[plezy](https://appshunter.io/ios/topics/plezy)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-08.*