Thermal stress mpa
thermal_stress_mpa
Thermal stress magnitude σ (MPa)
Scores if within ±3% of the reference value.
Computes the longitudinal thermal stress and force in continuously welded rail (CWR) using sigma = E * alpha * delta_T. Critical for managing rail buckling risk in hot conditions and rail pull-apart risk in cold conditions, per AREMA Chapter 5 and ARTC ETS-05-00.
with-tool: The model is given an executable Python calculator script.
One template produces many comparable benchmark tasks while keeping the scoring contract fixed.
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The reusable contract shown on this page.
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An archetype and site context are sampled.
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Inputs may be hidden at harder tiers.
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The model responds with the declared outputs.
Inputs the model receives, and the outputs it is scored on.
4 inputs
Included directly in every task prompt.
Rail area
rail_area_mm2
Rail cross-sectional area A
Temperature change
temperature_change_c
Temperature change from neutral temperature ΔT = T_rail − T_neutral
Sampled from the scenario and inferable from its description.
Thermal expansion coeff micro per c
thermal_expansion_coeff_micro_per_c
Coefficient of linear thermal expansion α
Derived from the archetype scenario. Hidden at hard difficulty.
Elastic modulus
elastic_modulus_mpa
Modulus of elasticity E of rail steel
Derived from the archetype scenario. Hidden at hard difficulty.
3 outputs
thermal_stress_mpa
Thermal stress magnitude σ (MPa)
Scores if within ±3% of the reference value.
thermal_force_kn
Thermal force magnitude F (kN)
Scores if within ±3% of the reference value.
stress_state
Stress state: 1.0 = compression, -1.0 = tension, 0.0 = neutral
Scores if within ±1% of the reference value.
Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.
All inputs given
All parameters given, moderate temperature changes on mainline corridors
All inputs given
All parameters given, any corridor type including extreme inland and alpine conditions
Some inputs hidden
Material properties hidden — agent must infer E and α for standard rail steel from engineering knowledge
Hidden inputs
Prompt replacement text
The rail is standard carbon-manganese rail steel on a {{ archetype.description }} ({{ archetype.site_context }})
The exact instruction and parameter contract used to generate this task, pinned to the published library source.
/workspace
Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.
1You are a senior civil engineer specializing in railway track engineering and continuously welded rail (CWR) design.2 3## Problem4 5Determine the thermal stress, thermal force, and stress state (compression or tension) in a continuously welded rail due to temperature change from the neutral (stress-free) temperature.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Rail cross-sectional area (A) | {{ rail_area_mm2 }} | mm² |12| Temperature change from neutral (ΔT) | {{ temperature_change_c }} | °C |13{% if thermal_expansion_coeff_micro_per_c is defined %}14| Coefficient of thermal expansion (α) | {{ thermal_expansion_coeff_micro_per_c }} | ×10⁻⁶ per °C |15{% endif %}16{% if elastic_modulus_mpa is defined %}17| Modulus of elasticity (E) | {{ elastic_modulus_mpa }} | MPa |18{% endif %}19{% if archetype_description is defined %}20 21### Site Conditions22 23{{ archetype_description }}24{% endif %}25 26{% if tool_available %}27## Available Tool28 29A thermal stress calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:30 31```bash32python3 /workspace/{{ meta.name }}_calc.py --help33```34 35You may use this tool to verify your calculations or compute values directly.36{% endif %}37 38## Required39 40Calculate the following:41 421. Thermal stress magnitude σ (MPa)432. Thermal force magnitude F (kN)443. Stress state: 1.0 if compression (rail hotter than neutral), -1.0 if tension (rail cooler than neutral), 0.0 if neutral45 46## Applicable Standards47 48- AREMA Manual for Railway Engineering, Chapter 5 (Track)49- UIC Code 720 R (Laying and Maintenance of CWR Track)50- ARTC Engineering Track Standard ETS-05-0051 52## Constraints53 54- No internet access is available. Work from engineering knowledge and the provided tool.55- Use the standard thermal stress formula for restrained rail:56 - σ = E × α × |ΔT|57 - where E is the modulus of elasticity (MPa), α is the coefficient of thermal expansion (per °C), ΔT is the temperature change from neutral (°C)58 - Report σ as a positive magnitude regardless of sign59- Calculate thermal force:60 - F = σ × A / 100061 - where A is the rail cross-sectional area (mm²), F is in kN62 - Report F as a positive magnitude63- Determine stress state from the sign of ΔT:64 - If ΔT > 0 (rail hotter than neutral): compression → report 1.065 - If ΔT < 0 (rail cooler than neutral): tension → report -1.066 - If ΔT = 0: neutral → report 0.067{% if elastic_modulus_mpa is not defined %}68- For standard rail steel: E ≈ 207,000 MPa (typical for carbon-manganese rail steel)69{% endif %}70{% if thermal_expansion_coeff_micro_per_c is not defined %}71- For standard rail steel: α ≈ 11.5 × 10⁻⁶ per °C72{% endif %}73 74## Output Format75 76Show your step-by-step working in Markdown. At the end of your solution, include a JSON block with your final answers in exactly this format:77 78```json79{80 "thermal_stress_mpa": <numeric_value>,81 "thermal_force_kn": <numeric_value>,82 "stress_state": <numeric_value>83}84```85 86Write your complete solution to `/workspace/output.md`.87 Each generated task is drawn from one of these realistic scenario bands.
Site contexts ground each scenario in a real locale the model can use to infer hidden values.
hot_inland
Hot inland corridor with large positive temperature rise above neutral
cold_alpine
Cold alpine or highland corridor with large negative temperature drop below neutral
coastal_temperate
Coastal temperate corridor with moderate temperature variation
tropical_north
Tropical northern corridor with sustained high temperatures above neutral
artc-broken-hill-corridor-hot-inland-preview — hard difficulty, some inputs hidden.
Hot inland corridor with large positive temperature rise above neutral. artc-broken-hill-corridor. Required outputs: thermal_stress_mpa, thermal_force_kn, stress_state
Scenario context and visible inputs.
Executable tool: thermal-stress-calculation_calc.py
Inputs withheld at this difficulty.
Elastic modulus mpa
elastic_modulus_mpa
Thermal expansion coeff micro per c
thermal_expansion_coeff_micro_per_c
Stand-in text in the prompt
The rail is standard carbon-manganese rail steel on a {{ archetype.description }} ({{ archetype.site_context }})
The scored JSON answer schema.
{
"thermal_stress_mpa": <number>,
"thermal_force_kn": <number>,
"stress_state": <number>
}