Mechanical Engineering · Structures and materials / Principles and inquiry
Beam deflection experiment guide
Change material, section and support to compare magnified deflection curves.
How does it work?
For the same material and section, central-load deflection scales with span cubed.
Key relationship
δcenter = PL³/(48EI) · Irect = bh³/12
Try this investigation
- Change material, section and support to compare magnified deflection curves.
- Run and record each of the three reference settings.
- Change one variable and compare force, deformation or response with the reference records.
Interpreting your results
Why does a deeper section resist bending?
Larger second area moment · For the same material and section, central-load deflection scales with span cubed.
Assumptions and limitations
Small-deflection Euler–Bernoulli beam theory omits shear, buckling and yielding. Large-deflection results are outside its quantitative validity. Scene shows magnification. Do not reproduce real load tests.