Explicit analysis
Where it is
Section titled “Where it is”Not a setup-tree node. Embedded in the application.
Controls
Section titled “Controls”ANALYSIS
Section titled “ANALYSIS”Drop height
Section titled “Drop height”- Control: value (
ValueField) - Unit: m
- Value modes: none (plain entry)
- Shown when:
root.drop
The fall is not simulated - only the landing. The part starts just above the floor at the speed a fall from this height gives, sqrt(2gh), so the run spends its steps on the impact.
Velocity X
Section titled “Velocity X”- Control: value (
ValueField) - Unit: m/s
- Value modes: none (plain entry)
- Shown when:
!root.drop && !root.blast
Velocity Y
Section titled “Velocity Y”- Control: value (
ValueField) - Unit: m/s
- Value modes: none (plain entry)
- Shown when:
!root.drop && !root.blast
Velocity Z
Section titled “Velocity Z”- Control: value (
ValueField) - Unit: m/s
- Value modes: none (plain entry)
- Shown when:
!root.drop && !root.blast
The floor is a plane normal to +Z below the part, so a negative Z velocity is what hits it. A velocity with no floor is a body flying freely, which the validator refuses.
Rigid floor
Section titled “Rigid floor”- Control: on/off (
ToggleRow) - Shown when:
!root.drop
The in-app guidance depends on the case:
- An infinite rigid plane under the lowest node of the part - for a part standing on the ground. Off by default for a blast; a held part should use a fixed face instead.
- An infinite rigid plane under the lowest node of the part. A drop always has one; an impact may be into it or, later, into another part.
Floor clearance
Section titled “Floor clearance”- Control: value (
ValueField) - Unit: m
- Value modes: none (plain entry)
- Shown when:
root.drop || ExplicitState.floor
The gap between the lowest node and the floor when time starts. Small, so the run does not spend its steps on free flight; not zero, so the first step is not already a penetration.
Parts in contact
Section titled “Parts in contact”- Control: on/off (
ToggleRow) - Shown when:
root.partCount > 1 || root.ballistic
A contact pair between every two parts. Off means they ignore each other and pass through - which conserves momentum and energy perfectly, and answers nothing.
Contact friction
Section titled “Contact friction”- Control: value (
ValueField) - Value modes: none (plain entry)
- Shown when:
(root.partCount > 1 || root.ballistic) && ExplicitState.partsInContact
Coulomb friction on every contact pair. Zero is frictionless.
Part fired
Section titled “Part fired”Label changes with the case; the source gives these forms: Part fired, Moving part.
- Control: value (
ValueField) - Value modes: none (plain entry)
- Shown when:
root.partCount > 1 || root.ballistic
Which part the velocity is given to, numbered from 1 in the order the parts appear in the mesh. 0 gives it to every part - right for an assembly thrown as a whole, and wrong for a shot, where it sends the target away with the projectile.
CHARGE
Section titled “CHARGE”Face struck
Section titled “Face struck”- Control: choice (
ComboRow) - Options:
— - Shown when:
root.blast && StructuralJob.meshFaceGroups.length > 0
The side of the part that looks toward the charge. The rest of the part is not loaded - the blast wave is taken to strike this face and nothing else.
Charge
Section titled “Charge”- Control: value (
ValueField) - Unit: kg TNT
- Value modes: none (plain entry)
- Shown when:
root.blast
The mass of the charge as equivalent TNT. Another explosive is converted first by its TNT equivalence factor, which is published separately for pressure and for impulse - the two differ, so use the one for the quantity that governs the damage.
Charge X
Section titled “Charge X”- Control: value (
ValueField) - Unit: m
- Value modes: none (plain entry)
- Shown when:
root.blast
Charge Y
Section titled “Charge Y”- Control: value (
ValueField) - Unit: m
- Value modes: none (plain entry)
- Shown when:
root.blast
Charge Z
Section titled “Charge Z”- Control: value (
ValueField) - Unit: m
- Value modes: none (plain entry)
- Shown when:
root.blast
Where the charge is, in the part’s own coordinates. Z is up: a surface burst sits on the ground at this height, and only what stands above it is loaded.
- Control: choice (
ComboRow) - Options:
Free air,Surface burst - Shown when:
root.blast
Free air: a spherical charge with nothing near it. Surface burst: a hemispherical charge on the ground, which reflects the wave back up - it behaves like a free-air charge of about 1.7 to 1.8 times the mass.
RESTRAINT
Section titled “RESTRAINT”Fixed face
Section titled “Fixed face”- Control: choice (
ComboRow) - Options:
— - Shown when:
StructuralJob.meshFaceGroups.length > 0
GRAVITY
Section titled “GRAVITY”Gravity X
Section titled “Gravity X”- Control: value (
ValueField) - Unit: m/s²
- Value modes: none (plain entry)
Gravity Y
Section titled “Gravity Y”- Control: value (
ValueField) - Unit: m/s²
- Value modes: none (plain entry)
Gravity Z
Section titled “Gravity Z”- Control: value (
ValueField) - Unit: m/s²
- Value modes: none (plain entry)
−9.80665 is gravity downwards, which is the direction the floor is under.
Event duration
Section titled “Event duration”- Control: value (
ValueField) - Unit: s
- Value modes: none (plain entry)
How long to follow the impact. The time STEP is not asked for: an explicit code sets it from the smallest element and the speed of sound in the material (the Courant limit), and a finer mesh means smaller steps and a longer run.
Animation interval
Section titled “Animation interval”- Control: value (
ValueField) - Unit: s
- Value modes: none (plain entry)
How often a state is written. The results shown are the LAST state - the end of the event - with stress and plastic strain averaged from the elements onto the nodes.
Problems reported against this step
Section titled “Problems reported against this step”The application reports no problems against this step.
… marks a value the application computes at run time, so the source carries no fixed text for it.