Compendium

Engineering Library — Per-Note Schema

3 min read

Engineering Library — Per-Note Schema

Every note in Engineering/ follows this structure. The schema flexes slightly across three note-types (concepts, materials, components) noted below; share the same shape.

Frontmatter

---
title: "<Topic> — Engineering Reference"
created: <ISO 8601>
agent: claude-code
type: engineering-reference
topic: <canonical slug>
discipline: <mechanical | electrical | electronics | materials | control | structural | civil | chemical | biomedical | aerospace | manufacturing | software | industrial | thermal | fluids>
note_type: <concept | material | component | process | standard>
key_standards: [ASTM E8, ISO 6892-1, IEEE 519, ...]
units_system: <SI | US-customary | both>
tags: [engineering-reference, <topic-slug>, <discipline>, <note_type>, ...]
official_refs: [<url>, ...]
latest_revision: "<x.y (yyyy-mm)>"   # only if applicable
---

Body sections

Common sections (all note types)

1. At a glance

What this is, why an engineer uses it, where it sits in the design stack.

2. First principles

Underlying physics, chemistry, or math.

3. Practical math / design equations

The formulas you actually use. Worked numerical examples with units carried through.

4. Reference data

Tables, charts, typical values, code-allowable stresses, vendor specs.

Type-specific sections

Note type = material (e.g. “6061-T6 Aluminum”, “PETG”, “S355 Structural Steel”)

  • 5m. Composition & microstructure — chemistry, phases, grain structure, heat-treatment state.
  • 6m. Mechanical properties — yield, ultimate, modulus, Poisson, hardness, fatigue endurance, fracture toughness. With test methods and standards cited.
  • 7m. Thermal / electrical / chemical properties — conductivity, expansion coefficient, melting point, corrosion behaviour, dielectric constant, resistivity. As applicable.
  • 8m. Processing & joining — machining, forming, welding, casting, finishing, surface treatments.
  • 9m. Applications & selection trade-offs — when to choose this over alternatives.
  • 10m. Failure modes — what kills this material in service.

Note type = component (e.g. “Brushless DC Motor”, “MOSFET”, “Ball Bearing”)

  • 5c. Variants & topologies — sub-types, key distinguishing parameters.
  • 6c. Selection criteria — design parameters that drive the choice (current, torque, frequency, package, ratings).
  • 7c. Datasheet decoding — which numbers actually matter, which are marketing.
  • 8c. Drive / interface electronics — controllers, drivers, gate drives, power supplies.
  • 9c. Real parts & sourcing — named products with current pricing/availability tier (commodity / specialty / single-source).
  • 10c. Failure modes & derating — thermal, mechanical, electrical limits and how to design margin.

Note type = concept / process / standard (e.g. “Stress concentration factor”, “Casting”, “ISO 9001”)

  • 5p. Theory — derivation or formal statement.
  • 6p. Application — when to use, how to apply.
  • 7p. Edge cases & assumptions — where the theory breaks down.
  • 8p. Tools & software — what FEA / circuit-sim / PLC / etc. embeds this.

Common closing sections (all note types)

11. Cross-references

  • Adjacent engineering topics (Engineering/<other>)
  • Robotics applications (Robotics/<other>)
  • Description languages (Languages/Tier3/<family>)

12. Citations

  • Foundational textbooks (Beer/Johnston, Shigley, Sedra/Smith, Ogata, Callister, etc.)
  • Standards (ASTM/ISO/IEC/IEEE/SAE/ASME with revision year)
  • Vendor datasheets, NIST databases, MIL-HDBK references
  • Recent papers (DOI / arXiv)

Writing rules

  • SI first; US-customary in parentheses where common in industry (e.g. “100 MPa (14.5 ksi)”).
  • Always show units in worked examples. Failing to carry units is the #1 source of engineering bugs.
  • Cite test method when quoting a material property. “Yield = 276 MPa per ASTM E8 at 21 °C” — not “yield ≈ 40 ksi.”
  • Date version-sensitive standards. “ISO 9001:2015” — not “ISO 9001.”
  • Engineering judgement is a real section, not throwaway prose. Allowable stresses, factors of safety, derating, code requirements are the stuff that separates competent design from a textbook walkthrough.
  • Cross-link liberally to Robotics/ and Languages/Tier3/. Engineering touches everything; isolated notes age badly.

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