CALCULATORS / MATERIAL RESPONSE AND SELECTION

Notch stress screening calculator

Elastic notch factor supplied from a relevant reference.

materials-stress-concentration.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	peakMPa
	110
	88

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

peak stress budget110.00 MPa✓ passes

BASELINE INPUTS

nominal50 MPafactor2.2

CALCULATED

peak110 MPa

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Notch stress screening
# Scope: Elastic notch factor supplied from a relevant reference.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

nominal = 50 MPa
factor = 2.2

peak := nominal*factor [MPa]

check peak stress budget: peak <= 150 MPa

scenario alternative: nominal = 40 MPa

Calculated from your source · not saved

Baseline · Baseline

peak stress budget110.00 MPa ✓ passes

alternative · alternative

peak stress budget88.00 MPa ✓ passes

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

peak: peak = nominal*factor [MPa]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

nominal: 50 MPa
factor: 2.2

Calculated

peak: 110 MPa

Assumptions and limits

Elastic notch factor supplied from a relevant reference.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Notch stress screening. Inputs: nominal stress; geometry; selected concentration factor. Outputs: local stress estimate. Model scope: Screening with user-supplied or cited material properties. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: nominal stress, geometry, selected concentration factor
Outputs: local stress estimate
Modes: calculate, compare, sweep
Drawing: Material tradeoff plot

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS