calc_inertia_platetri: Moment of inertia tensor of a flat triangular plate In AvInertia: Calculate the Inertial Properties of a Flying Bird

Description

Reference: https://apps.dtic.mil/dtic/tr/fulltext/u2/a183444.pdf page 4 equations 2.16-2.20

Usage

 1 calc_inertia_platetri(pts, A, rho, t, desired_prop)

Arguments

 pts a matrix of the three 3D points that define a point on the triangular plate. Frame of reference: Muscle | Origin: VRP each point should be a different row as follows: pt1x, pt1y, pt1z pt2x, pt1y, pt2z pt3x, pt3y, pt3z A area of the triangular plate (m) rho density of the material (kg/m^3) t thickness of the plate (m) desired_prop a string containing either "I" or "CG" depending on the desired output

Value

a 3x3 matrix representing the moment of inertia tensor of a flat triangular plate about its center of gravity. Z axis defined as the normal to the input points.

Warning

The input points should be defined in a counterclockwise direction around the plate in the triangular plate frame of reference i.e. all z components should be equal

Christina Harvey

Examples

 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 # refer to the vignette library(AvInertia) # load data data(dat_id_curr, package = "AvInertia") data(dat_bird_curr, package = "AvInertia") data(dat_feat_curr, package = "AvInertia") data(dat_bone_curr, package = "AvInertia") data(dat_mat, package = "AvInertia") data(clean_pts, package = "AvInertia") # 1. Determine the center of gravity of the bird's torso (including the legs) dat_torsotail_out = massprop_restbody(dat_id_curr, dat_bird_curr) # 2. Calculate the inertia of the flight feathers about the tip of the calamus feather_inertia <- compute_feat_inertia(dat_mat, dat_feat_curr, dat_bird_curr) # 3. Determine the center of gravity of one of the bird's wings dat_wing_out = massprop_birdwing(dat_id_curr, dat_bird_curr, dat_bone_curr, dat_feat_curr, dat_mat, clean_pts, feather_inertia, plot_var = 0) # Visualize the center of gravity of each wing component in the x and y axis dat_wing_out = massprop_birdwing(dat_id_curr, dat_bird_curr, dat_bone_curr, dat_feat_curr, dat_mat, clean_pts, feather_inertia, plot_var = "yx") # or the y and z axis dat_wing_out = massprop_birdwing(dat_id_curr, dat_bird_curr, dat_bone_curr, dat_feat_curr, dat_mat, clean_pts, feather_inertia, plot_var = "yz") # 4. Combine all data and obtain the center of gravity, moment of inertia # and principal axes of the bird curr_full_bird = combine_inertialprop(dat_torsotail_out,dat_wing_out, dat_wing_out, dat_id_curr, dat_bird_curr, symmetric=TRUE)

AvInertia documentation built on July 22, 2021, 9:08 a.m.