Snow Load Stem Bending Stress Breakage Checker

Screen circular intact stem cantilever bending under caller transverse snow-weight lever arms and material stress limits; this elementary idealization does not predict tree breakage or certify public/work safety.

Description

A circular intact stem can be approximated as a cantilever under a transverse load.

A circular intact stem can be approximated as a cantilever under a transverse load. Bending stress scales strongly with stem diameter in this idealization.^[1]

When to use Snow Load Stem Bending Stress Breakage Checker

Use this tool to screen circular intact stem cantilever bending under caller transverse snow-weight lever arms and material stress limits; this elementary idealization does not predict tree breakage or certify public/work safety.

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.

How to use Snow Load Stem Bending Stress Breakage Checker and understand its results

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
Enter snowMassLoadsKg, loadLeverArmsM, stemDiametersM, gravityMPerSecondSquared, callerAllowableBendingStressPa using the field table and calculation rules, then run the tool.
Read modelStemBendingStressesPa, aboveCallerStressFlags. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
snowMassLoadsKg	Snow mass loads kg	list of number	Required
loadLeverArmsM	Load lever arms m	list of number	Required
stemDiametersM	Stem diameters m	list of number	Required
gravityMPerSecondSquared	Gravity m per second squared	number	Required
callerAllowableBendingStressPa	Caller allowable bending stress Pa	list of number	Required

Pair nonnegative snow kg and lever-arm meters with positive stem diameters and caller allowable Pa; use positive gravity. Return model stresses and flags only for strict exceedance of each supplied limit.

Paired lists must be nonempty and have equal lengths.

bending stress=32 × snow mass × gravity × lever arm/(πdiameter³)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
modelStemBendingStressesPa	Model stem bending stresses Pa	list of number
aboveCallerStressFlags	Above caller stress flags	list of number

json

{
  "input": {
    "snowMassLoadsKg": [
      10,
      20
    ],
    "loadLeverArmsM": [
      1,
      2
    ],
    "stemDiametersM": [
      0.1,
      0.2
    ],
    "gravityMPerSecondSquared": 10,
    "callerAllowableBendingStressPa": [
      1000000,
      1000000
    ]
  },
  "output": {
    "modelStemBendingStressesPa": [
      1018591.63578813,
      509295.817894065
    ],
    "aboveCallerStressFlags": [
      1,
      0
    ]
  }
}

Limitations and assumptions

Defects, taper, load geometry and dynamics are omitted. The screen does not predict actual tree breakage.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Ice Storm Canopy Retained Severity Percent: Audit measured retained live crown volume after storm against matched prestorm inventory and caller loss cutoff; canopy volume differs from shade/cover and observations do not establish future tree survival. For a complementary task, use Thermal Shock Sensitivity Checker: Screen caller measured temperature contrast with a fully constrained isotropic thermoelastic stress proxy and caller strength limit; geometry, anisotropy, defects and transient heat transfer omitted, no safe heating/cleaning advice.

References

Snow Load Stem Bending Stress Breakage Checker — tool.io

Similar or alternative tools

Ice Storm Canopy Retained Severity Percent
Audit measured retained live crown volume after storm against matched prestorm inventory and caller loss cutoff; canopy volume differs from shade/cover and observations do not establish future tree survival.
Thermal Shock Sensitivity Checker
Screen caller measured temperature contrast with a fully constrained isotropic thermoelastic stress proxy and caller strength limit; geometry, anisotropy, defects and transient heat transfer omitted, no safe heating/cleaning advice.