handcalcs.py

# Imports
import json, numpy as np, pandas as pd

# Parameters
params = json.load(open("params.json"))
propdf = pd.read_csv("output/mechprops.csv", header=None)
k_tot = propdf[1][0]
m = propdf[2][0]
L_plate = params["L_plate"]
n_cont = params["n_cont"]
L_cont = params["L_cont"]
A_gate = L_plate**2 - n_cont * L_cont**2 * 2.5
t_cont = params["t_cont"]
t_gap = params["t_gap"] + params["t_sp"] / params["K_sp"]
F_A = 0

# Constants
eps_0 = 8.85418782E-12 # m^-3 kg^-1 s^4 A^2
E_poly = 145E9 # Pa
rho_poly = 4126 # kg/m^3
rho_W = 55e-9 # Ohm m (W)
H_W = 1.1e9 # Pa
lambda_W = 33e-9 # m
k = 1 # dielectric constant of air
xi_W = 0.25 # elastic contact constant

# Calculations
V_pi = ((8 * k_tot * t_gap**3)/(27 * k * eps_0 * A_gate))**0.5
V_po = ((2 * (k_tot * (t_gap - t_cont) - F_A) * t_cont**2)/(k * eps_0 * A_gate))**0.5

# Results
print("Pull-in voltage: %s V" % V_pi)
print("Pull-out voltage: %s V" % V_po)

# Contact force/resistance
F_cont = np.genfromtxt("output/fcont.csv", delimiter=',', usecols=range(1,16+1))
print("Mean contact force: %s N" % F_cont.mean())
print("Stdev. contact force: %s N" % F_cont.std())
A_r = F_cont / (xi_W * H_W)
R_cont = 4 * rho_W * lambda_W / (3 * A_r)
print("Mean contact resistance: %s Ohm" % R_cont.mean())
print("Stdev. contact resistance: %s Ohm" % R_cont.std())
print("Mean contact conductance: %s S" % (1/R_cont).mean())
print("Stdev. contact resistance: %s S" % (1/R_cont).std())