onept_normal.m

Matlab中实现轮对分析的程序以及相关的程序包,可以实现火车轮轨接触关系的分析

% M-file name: onept_normal.m
% M-file type: Function file

% This function file computes the normal forces acting on the left and the right wheels due to
% the interaction between wheel and rail. This calculation is valid for a single-point contact
% condition between the wheel and the rail. The inputs to the function are the longitudinal,
% lateral, and vertical creep forces, the lateral creep moments, rolling radii and contact angles at
% the left and the right wheel contact patches, and the wheelset yaw displacement and velocity.
% The outputs are the normal forces on the left and the right wheels resolved in longitudinal,
% lateral, and vertical directions.

% The outputs given by this function are called by the function file 'wheelset.m'.

function [Fny1,Fnz1,Fny2,Fnz2]=onept_normal(x2,x4,delta1,delta2,r1,r2,Fcx1,Fcx2,Fcy1,Fcy2,Fcz1,Fcz2,Mcy1,Mcy2)

% Parameters used for simulation

% V: Forward velocity of wheelset (m/sec)
% a: Half of track gage (m)
% r0: Centered rolling radius of the wheel (m)
% mw: Mass of wheelset (kg)
% Iwy: Pitch principal mass moment of inertia of wheelset (kg-m2)
% g: Acceleration due to gravity (m/s2)
% N: Axle load (N)

% Indicating the global nature of the variables This means that the value of the variables need
% not be specified in this function file. This value is automatically obtained from the main file
% 'single_wheelset.m'.

global V a r0 mw Iwy g N;

% Computing the normal forces at the left and right wheel-rail contact patches

F=-Fcz1-Fcz2+mw*g+N;
M=a*(Fcz2-Fcz1)-r1*(Fcy1-x2*Fcx1)-r2*(Fcy2-x2*Fcx2)-x2*(Mcy1+Mcy2)-Iwy*(V/r0)*x4;
vl=F*(a*cos(delta2)-r2*sin(delta2))+M*cos(delta2);
vr=F*(a*cos(delta1)-r1*sin(delta1))-M*cos(delta1);
del1=2*a*cos(delta1)*cos(delta2)-r2*cos(delta1)*sin(delta2)-r1*sin(delta1)*cos(delta2);
Fnl=vl/del1;
Fnr=vr/del1;

% The normal forces calculated above are normal to the contact patch plane. These forces are
% resolved in the longitudinal, lateral, and vertical directions in the track coordinate system. The
% variables calculated below are passed to the function 'wheelset'.

% Resolving normal forces at the left and right wheel contact patches

Fny1=-Fnl*sin(delta1);
Fnz1=Fnl*cos(delta1);
Fny2=Fnr*sin(delta2);
Fnz2=Fnr*cos(delta2);