material-testing

name	material-testing
description	Skill for planning and specifying mechanical material tests per ASTM standards
allowed-tools	["Read","Write","Glob","Grep","Bash"]
metadata	{"specialization":"mechanical-engineering","domain":"science","category":"materials-testing","priority":"medium","phase":8,"tools-libraries":["Instron","MTS","Universal testing machines","ASTM standards"]}

Material Testing Planning Skill

Purpose

The Material Testing Planning skill provides capabilities for planning and specifying mechanical material tests per ASTM standards, enabling proper test specimen design, test matrix development, and data analysis for property determination.

Capabilities

• Tensile testing specification (ASTM E8)
• Hardness testing methods (Rockwell, Brinell, Vickers)
• Impact testing (Charpy, Izod) per ASTM E23
• Fatigue testing (ASTM E466, E606)
• Test specimen design and preparation
• Test matrix development and optimization
• Data analysis and property determination
• Test report generation

Usage Guidelines

Tensile Testing (ASTM E8/E8M)

Specimen Design

1. Standard Specimens

   Type	Gauge Length	Gauge Width	Application
   Sheet (flat)	50 mm	12.5 mm	Sheet/plate < 6 mm
   Round	50 mm	12.5 mm dia	Bar/rod stock
   Subsize	25 mm	6 mm	Limited material

2. Specimen Preparation

   • Machine finish on gauge section
   • Radius transitions per standard
   • Measure dimensions before test
   • Mark gauge length

Test Parameters

Strain rate: 0.015 mm/mm/min (yield)
            0.05-0.5 mm/mm/min (ultimate)
Temperature: Ambient (23 +/- 5 C) or specified
Extensometer: Class B-1 or better

Properties Determined

• Yield strength (0.2% offset method)
• Ultimate tensile strength
• Elongation at fracture
• Reduction of area
• Young's modulus

Hardness Testing

Test Methods

Method	Scale	Load	Application
Rockwell B	HRB	100 kgf	Soft steel, copper
Rockwell C	HRC	150 kgf	Hardened steel
Brinell	HB	3000 kgf	Castings, forgings
Vickers	HV	1-120 kgf	All materials
Knoop	HK	10-1000 gf	Thin sections, coatings

Test Considerations

1. Surface Preparation

   • Clean, flat surface
   • Minimum surface roughness
   • No decarburization

2. Spacing Requirements

   Minimum indent spacing: 3 x indent diameter
   Minimum edge distance: 2.5 x indent diameter
   Minimum thickness: 10 x indent depth
   

Impact Testing (ASTM E23)

Charpy V-Notch

1. Specimen Dimensions

   Standard: 10 x 10 x 55 mm
   Subsize: 10 x 7.5/5/2.5 x 55 mm
   Notch: 45 degree V, 2 mm deep, 0.25 mm radius
   

2. Test Temperature

   • Room temperature
   • Transition curve (multiple temperatures)
   • Minimum design metal temperature

3. Properties Determined

   • Absorbed energy (Joules)
   • Lateral expansion (mm)
   • Percent shear fracture

Fatigue Testing

High-Cycle Fatigue (ASTM E466)

1. Test Types

   • Rotating beam (R = -1)
   • Axial load (R = 0, R = -1, R = 0.1)
   • Strain-controlled (low cycle)

2. S-N Curve Development

   Minimum 12-15 specimens for S-N curve
   3 stress levels minimum
   Runout at 10^6 or 10^7 cycles
   

Strain-Controlled Fatigue (ASTM E606)

1. Specimen Design

   • Uniform gauge section
   • Anti-buckling for compression
   • Precise alignment

2. Test Parameters

   • Strain amplitude range
   • Strain rate
   • Mean strain (if applicable)

Test Matrix Development

Statistical Considerations

Purpose	Minimum Tests	Basis
Typical properties	3	Average
Design allowables (A-basis)	100+	99%/95% confidence
Design allowables (B-basis)	30+	90%/95% confidence
S-basis	1	Specification minimum

Test Matrix Template

Material: ____________
Specification: ____________
Heat/Lot: ____________

| Test Type | Orientation | Temperature | Specimens | Standard |
|-----------|-------------|-------------|-----------|----------|
| Tensile   | L           | RT          | 3         | ASTM E8  |
| Tensile   | T           | RT          | 3         | ASTM E8  |
| Hardness  | Surface     | RT          | 5 loc     | ASTM E18 |
| Impact    | L-T         | -40 C       | 3         | ASTM E23 |

Process Integration

• ME-015: Material Testing and Characterization

Input Schema

{
  "material": {
    "name": "string",
    "specification": "string",
    "heat_lot": "string",
    "form": "plate|bar|forging|casting"
  },
  "test_requirements": {
    "tensile": "boolean",
    "hardness": "boolean",
    "impact": "boolean",
    "fatigue": "boolean"
  },
  "orientations": ["L", "T", "S"],
  "temperatures": "array (C)",
  "basis": "typical|A-basis|B-basis|S-basis"
   

Output Schema

{
  "test_plan": {
    "test_matrix": "array of test specifications",
    "specimen_drawings": "array of references",
    "total_specimens": "number",
    "estimated_material": "number (kg)"
  },
  "specimen_requirements": {
    "dimensions": "object",
    "quantity": "number",
    "preparation_notes": "string"
  },
  "test_procedures": "array of procedure references",
  "data_analysis_plan": {
    "properties_to_calculate": "array",
    "statistical_methods": "array"
  }
}

Best Practices

1. Follow applicable ASTM standards exactly
2. Document specimen location and orientation
3. Calibrate equipment per standard requirements
4. Control test environment (temperature, humidity)
5. Maintain chain of custody for specimens
6. Archive raw data and specimens per requirements

Integration Points

• Connects with Material Selection for property validation
• Feeds into Failure Analysis for reference data
• Supports Test Correlation for model validation
• Integrates with Quality for material certification