🎲Results

The result components read the model that comes back out of Run Analysis or Natural Vibration. There is no separate result object — the analysis attaches its output to the AlpacaModel itself.

Underneath, results are recorded by the MPCO recorder written by M. Petracca and G. Camata at ASDEA Software Technology, and read back from the recorder.mpco file that the analysis leaves beside the Grasshopper document.

Components in this tab

Component	Nickname	Reads
Nodal Displacements	Nodal Displacements	Displacement, rotation, velocity, acceleration at every node.
Reaction Forces	Reaction Forces	Force and moment at every support, in the support's own axes.
Beam Forces	Beam Forces	N, Vy, Vz, Mx, My, Mz along every beam.
Shell Forces	Shell Forces	Membrane, bending and shear resultants on every shell.
Brick Stresses	Brick Stresses	The six stress components and Von Mises on every solid.
Modal Analysis Report	Modal Analysis Report	Masses, centre of mass, participation factors and ratios.

Nodal Displacements

Reads displacement, rotation, velocity and acceleration at every node of an analysed model.

One value per node, in global axes, in the order the nodes were assembled. Velocity and acceleration are recorded by a transient analysis only. After a Natural Vibration analysis, Step picks the mode and Displacement and Rotation are that mode's shape.

Reaction Forces

Reads the force and the moment carried by every support of an analysed model.

One value per support, given in the support's own axes, so a Support placed on a Plane reports along that plane rather than along the global axes. SupportPosition gives both where each support sits and the frame its reactions are in.

Beam Forces

Reads the internal forces along every beam element of an analysed model — axial force, two shears, torsion and two bending moments.

Each output is a tree with one branch per element, holding the values at the element's integration sections from the I end to the J end, in local axes. N is positive in tension.

Shell Forces

Reads the stress resultants of every shell element of an analysed model — membrane forces pxx, pyy and pxy, bending moments mxx, myy and mxy, and transverse shears vxz and vyz.

All of them per unit width and in the shell's local axes. Each output is a tree with one branch per element, holding the values at the element's integration points.

Brick Stresses

Reads the stress state of every solid element of an analysed model — the six components of the stress tensor plus the Von Mises equivalent stress.

One value per element, in the element's local axes — an SSP Brick and a Four Node Tetrahedron both have a single integration point, so there is nothing to sample along. These are the only two element types it reads.

Modal Analysis Report

Splits the report written by a Natural Vibration analysis into its sections: eigenvalues, total and free mass, centre of mass, modal participation factors, participating masses and their ratios.

Every output is one section of the report as text, ready for a panel. The cumulative ratio is the one to check against a code threshold such as 90%.

Common inputs

Every component except the Modal Analysis Report shares the same three inputs:

Name	Nick	Type	Default	Description
AlpacaModel	AlpacaModel	Model	—	The analysed model.
History	History	Boolean	false	Read every recorded step instead of one. Step is then ignored.
Step	Step	Integer	0	Which analysis step to read. For a modal model, which mode.

History is how you get a time history out in one go. With it set, each output gains a step index in front of whatever index it already had:

Component	With History = false	With History = true
Nodal Displacements	a list, one item per node	a tree {step}, that step's value per node
Reaction Forces	a list, one item per support	a tree {step} for the force and the moment; SupportPosition stays a flat list, since supports do not move
Beam Forces	a tree {element}	a tree {step; element}
Shell Forces	a tree {element}	a tree {step; element}
Brick Stresses	a list, one item per element	a tree {step}, that step's value per element

How many steps there are to read is set by NumIncr on Analysis Step.

Reading the numbers

• Forces are in kN, moments in kN·m, lengths in m, rotations in rad.

• Beam and shell results come back as a data tree, one branch per element; brick stresses are a flat list, one value per element.

• Beam and shell results are in local axes; nodal results are in global axes; reactions are in the support's own axes.

To see any of this in the viewport rather than as numbers, use the matching component in Visualisation.