Formula used
Linear elastic formulas assume axial loading, small strain, constant properties, and negligible stress concentrations.
How to use this calculator
- Select the calculation mode matching your engineering problem.
- Choose a material preset or enter custom material properties.
- Enter member dimensions, force, temperature, or target values.
- Select compatible input and output units for each quantity.
- Review safety settings, then calculate and inspect all warnings.
- Copy, print, or export the complete calculation record.
Example data
| Example | Inputs | Use |
|---|---|---|
| Steel rod | 50 kN, 2,000 mm, 20 mm diameter, 200 GPa | Uniform axial elongation |
| Heated aluminum bar | 1.5 m, α = 23.1 × 10⁻⁶/K, ΔT = 60°C | Thermal elongation |
| Composite member | Steel and aluminum segments carrying 25 kN | Segmented calculation |
| Tapered bar | 30 mm to 20 mm diameter, 1,200 mm long | Tapered circular model |
Calculation history
Frequently asked questions
What is elongation?
Elongation is the change in member length caused by load, temperature, self-weight, or imposed strain.
When is FL divided by AE valid?
Use it for prismatic members under concentric axial load within the linear elastic range.
How is compression handled?
Compression uses a negative sign, so the reported deformation represents member shortening.
Can materials differ between segments?
Yes. Enter separate length, area, modulus, force, thermal coefficient, and temperature values.
What does percentage elongation mean?
It equals engineering strain multiplied by one hundred and expresses relative length change.
Why does the tool show a yield warning?
Stress above yield strength can cause permanent deformation, invalidating simple elastic formulas.
Does self-weight depend on area?
For a uniform hanging member, area cancels when density and modulus remain constant.
Can temperature change be negative?
Yes. A negative temperature change usually produces thermal contraction for positive coefficients.
How are hollow sections checked?
The tool requires a positive outer diameter and a smaller nonnegative inner diameter.
Are material preset values exact?
No. They are typical values and should be replaced with certified project data.