Engineering

Mechanical and civil engineering fundamentals: beams, shafts, pumps, heat transfer, fluid flow and control. 49 calculators, aimed at checking a number you already have rather than replacing a design process.

Worth saying plainly, because these pages return structural numbers: nothing here is a substitute for a licensed engineer’s calculation on anything that holds a load people stand under. Use them to sanity-check, to size a first guess, or to see how sensitive a result is to one input.

Beam deflection shows why that sensitivity matters. Deflection scales with the cube of span for a point load and the fourth power for a distributed one, so a beam that is 20% longer deflects roughly twice as much under the same distributed load. Almost every “it felt fine on paper” floor bounce traces back to that exponent.

Column buckling has the failure mode people forget: a slender column fails by buckling long before the material reaches its yield stress, so a strength calculation alone says the column is fine right up until it folds. End conditions swing the critical load by a factor of 16 between fixed-fixed and pinned-free, which is why the page asks rather than assuming pinned.

Factor of safety lists the customary values by application, since 1.5 and 10 are both correct answers depending on what fails and who is standing near it.