Pfc Flat Joint Brittle Rock

PFC Flat Joint Brittle Rock

This skill turns Chapter 5.4-5.5 into a reusable route for flat-joint modeling, formula retention, test design, and plotting contracts.

When to use

Use this skill when the user wants to:

• explain why flat-joint models improve on standard BPM
• retain core FJM or FJM3D formulas and parameter logic
• discuss Brazilian test, uniaxial tension, triaxial compression, or core discing
• analyze the effect of installation gap ratio, crack density, or local strength parameters
• organize plots for crack evolution, parametric studies, or discing patterns

First rules

1. State which standard BPM limitation the flat-joint feature is solving.
2. Keep the contact-installation logic separate from the element failure logic.
3. When discussing parametric studies, define which parameter is being swept and which observable is measured.
4. For Brazilian and core-discing plots, state the loading path and stress state explicitly.
5. Reuse Chapter 5.5 conclusions as summary guidance, not as a standalone skill.

Default workflow

1. Recover the mechanism upgrades

Read references/theory.md for the four main flat-joint upgrades: self-locking, rotation resistance, stress-dependent shear strength, and prefabricated cracks.

2. Retrieve the key formulas

Read references/formulas.md for installation-gap logic, element stress expressions, bonded-element strength envelope, and residual friction expression.

3. Plan the tests and plots

Read references/plotting.md for the default figure family:

• FJM structure schematic
• parameter-effect plots
• Brazilian-test figures
• crack-evolution figures
• core-discing pattern figures

4. Trace chapter provenance

Read references/chapter-map.md when you need the exact section, figure, or experiment mapping inside Chapter 5.4-5.5.

Read next

• references/theory.md
• references/formulas.md
• references/plotting.md
• references/chapter-map.md

Output contract

For a complete response or delivery, prefer these artifacts:

• a short explanation of which FJM mechanism fixes which BPM defect
• the core formula block with symbol definitions
• a test matrix for uniaxial, triaxial, Brazilian, or discing cases
• a figure list with explicit axes, inputs, and output names

Local Contents

• references/chapter-map.md: topic and workflow routing for flat-joint brittle-rock cases.
• references/formulas.md: strength, stiffness, and calibration formulas.
• references/plotting.md: required plots and publication output conventions.
• references/theory.md: flat-joint model assumptions and interpretation notes.