Uniformly distributed load acts on a plate supported along two opposite edges, rather than only at four table corners.
L is support span, B effective width and t thickness. Load mass is m; density ρ adds plate self-weight.
Support and loading model
Two opposite supported edges, uniform payload
Span / overhang L
1,000 mm
Effective load-carrying width B
600 mm
Top thickness t
12 mm
Additional payload mass m
50 kg
Top density ρ (example)
2,700 kg/m³
Young modulus E (example)
70 GPa
Bending stress limit for comparison
80 MPa
Deflection limit δlim
3 mm
Check downward deflection and bending stress first. Capacity also depends on the entered comparison limits.
σmax · Bending stress at entered payload
5.91123 MPa
δmax · Maximum deflection at entered payload
1.46608 mm
Additional payload within stated limits
122.653 kg
Blue marks inputs; orange marks outputs. These diagrams explain the fixed example below; dimensions and deformation are not drawn to physical scale.
Advertisement
2. Example inputs
Support and loading modelWhat goes here?
Choose the option matching your mechanism and diagram. A different model can change required inputs and applicable results.
Two opposite supported edges, uniform payload
Span / overhang LWhat goes here?
Use the dimension marked in the diagram. Distinguish radius from diameter, bore from outside diameter, and overall length from support span.
1,000 mm
Effective load-carrying width BWhat goes here?
Use the dimension marked in the diagram. Distinguish radius from diameter, bore from outside diameter, and overall length from support span.
600 mm
Top thickness tWhat goes here?
Use the dimension marked in the diagram. Distinguish radius from diameter, bore from outside diameter, and overall length from support span.
12 mm
Additional payload mass mWhat goes here?
This is mass, including fixtures or loads that move with it where required. Kilograms describe mass; newtons describe force.
50 kg
Top density ρ (example)What goes here?
Mass per unit volume, used in mass=density×volume.
Use properties for the material/fluid, temperature, pressure and moisture. The table compares magnitudes, not certified material values. Use actual material volume for hollow parts.
Choose values for actual contact, lubrication, temperature and other conditions. These initial values are examples.
2,700 kg/m³
Young modulus E (example)What goes here?
E describes axial stiffness and G shear stiffness; neither is yield strength or allowable stress.
Use the actual material, temperature and direction. Table entries are comparisons, not material specifications. For isotropic elasticity, check consistency with G=E/[2(1+ν)].
Choose values for actual contact, lubrication, temperature and other conditions. These initial values are examples.
70 GPa
Bending stress limit for comparisonWhat goes here?
This is the stress comparison criterion. Yield stress differs from allowable stress; match material condition, use and safety factor.
80 MPa
Deflection limit δlimWhat goes here?
Use the dimension marked in the diagram. Distinguish radius from diameter, bore from outside diameter, and overall length from support span.
3 mm
These are fixed teaching inputs. Coefficients, properties and comparison limits are not recommendations. Enter your conditions in the calculator.
3. Results for this example
Bending stress at entered payload
5.91123 MPa
Maximum deflection at entered payload
1.46608 mm
Additional payload within stated limits
122.653 kg
Read actual stress and deflection first, then the capacity estimate for the entered criteria. Example properties and allowable values are not design standards.
4. Which formula is used?
I = Bt³/12; Z = Bt²/6; Wself = ρBtLg; P = mg; Mmax = (P+Wself)L/8; δmax = 5(P+Wself)L³/(384EI); σmax = Mmax/Z
Table units are not always the units required in the formula. The calculator converts selected units to its internal base units before computing.
Advertisement
Assumptions and exclusions
A homogeneous constant-thickness top is modelled as a one-way beam of width B. Supported edges must be continuous across the width. The centre load is a line load spread across the full width, not a small-area point load. Four isolated corner legs, two-way four-edge plate action, plywood/wood anisotropy, reinforcement, shear and local deformation are excluded. Legs, frame, joints, floor and tipping require separate checks. Specify applicable stress and deflection limits.
