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Users Manual for Program NPICK





Table of contents

Introduction

Input data commands
  Summary of all main commands
  Detailed description of all main commands

Command line options

File formats
  File formats from the NPICK program
  File formats from the FEM program
    File formats from Patran


Example 1:  Master input data file for program NPICK

Example 2:  Create a npick result file manually




Introduction

Program NPICK reads modal results from a FEM program and rewrites these results suitable for the CALC-program. Program NPICK shall be used when flexibilities in a mass should be taken into consideration. In the CALC input data file, the user models the masses as rigid masses, after executing program NPICK the masses have become flexible.
Three files are produced by program NPICK the three files have extension .npickr, .npickm and .npicki. File .npickr is the file which shall be inserted in the CALC input data file. File .npickm is a message file showing the user how program NPICK has treated the FEM results. Finally file .npicki contains nod numbers in the FEM-model, if the user wants to use the same set of nodes as in an earlier calculation.




Input data commands

Input data are read in free format, valid separators between the input values are <space>, <comma>, <tab>, <equal sign> or <carriage return>. The commands can be written both in lower and upper case letters. The operation of the program is controlled by the commands described below; some of the commands also need arguments.




Summary of all main commands


FEM_GEOM_FILE = Geometry file from the FEM program.
FEM_RES_FILE = Mode shape files from the FEM program.
FEM_XMIRROR = Copy the FEM-model in a yz-plane.
FEM_YMIRROR = Copy the FEM-model in a xz-plane.
FLEX_BODY = Name of the mass in the runf-file which shall be flexible.
HEAD = Reading of header lines.
IDEBUG = Definition of different levels of debug printing.
INSERT = Definition of include-files.
MPF = Definition of load-cases for the calculation of Modal Participation Factor.
NODE_INTPL = Forces NPICK to interpolate in user defined nodes in the FEM results.
NPICK_FILE = Name of NPICK result file.
ORIGO_CALC_FEM = Distance between the origin in the CALC-model and the FEM-model.
PASS_AREA = Defines the area where the passengers are located (if FLEX_BODY is a carbody of a vehicle).
PASS_MASS = The weight of all passengers (if FLEX_BODY is a carbody of a vehicle).
PASS_MODEL = Type of model to be used for the passengers (if FLEX_BODY is a carbody of a vehicle).
READ_RUNf = Name of the runf-file containing the vehicle model.
REL_DAMP = Fraction of critical damping of the eigenfrequencies .
ROT_CALC_FEM = Rotation of the coordinate system between the CALC-model and the FEM-model.
SCALE_CALC_FEM = Scale factor between the CALC-model and the FEM-model.
STOP = Stops further input data reading.
TOL_NODE_DMIN = Sets the node min distance selection tolerance.
TOL_NODE_DMAX = Sets the node max distance selection tolerance.
TOL_NODE_LMIN = Sets the min value of the shape functions of the tetrahedron.
TOL_NODE_LMAX = Sets the max value of the shape functions of the tetrahedron.



Detailed description of all main commands



FEM_GEOM_FILE= fem_geom_type*20, filename*132

Geometry file from the FEM program.
The command has two input data parameters:
fem_geom_type = Type of FEM-data to be read. For the moment "Patran" is the only available format. When fem_geom_type is equal to "Patran", program NPICK expects to read a Patran Neutral File.
(ANSYS node-files can be translated into PATRAN format, with program "a2p_geom". Program "a2p_geom" is an interactive program which starts by giving command "a2p_geom" in a terminal window.)
filename = The name of the Patran Neutral File.


FEM_RES_FILE= fem_res_type*20, filename(1:100)*132

Result file from the FEM program.
The command has two input data parameters:
fem_res_type = Type of FEM-data to be read. For the moment "Patran" is the only available format. When fem_geom_type is equal to "Patran", program NPICK expects to read a Patran Nodal Results Files.
(ANSYS node-displacement result-files can be translated into PATRAN format, with program "a2p_disp". Program "a2p_disp" is an interactive program which starts by giving command "a2p_disp" in a terminal window.)
filename = The names of the Patran Nodal Results Files. Number of files defines how many eigenmodes that will be taking into consideration.


FLEX_BODY= bodyname*80

The name of the mass which shall be supplied with flexible modes. The name refers to the mass defined in READ_RUNf.



HEAD= ihead, text*80

Reading of header lines, The command has two arguments:
ihead = Number of header line (Maximum 10).
text = The header line.

If FEM_GEOM_FILE equals "Patran", will the first header line be obtained from the Patran Neutral File.



IDEBUG
                        
 IDEBUG= db_level       
                        
Definition of different levels of debug printing.
The user can select between the following debug levels:
0 = No debugging information is written.
1 = Write the memory dump to file npick.out.
2 = Write the memory dump to file npick.out, and debugging text on standard output, showing how program NPICK works. If a tetrahedron not can be created, the debugging text might help you understanding why NPICK fails.

Declared Integer*4   Default= 0

INSERT
                        
 INSERT= ins_file       
                        

Redirects input reading to file ins_file. After reading EOF on ins_file, the reading will continue with next command in current input data file.

Declared Character*132   Default= Blank



MPF

Definition of load-cases for the calculation of Modal Participation Factor. Defining a number of load cases for the Modal Participation Factors, helps the user to characterize different modes of vibration in the flexible body. Each load-case is given an unique name in order to easier identify the load case in the printing in the message file. Please look in the example below in order to get an idea of how different modes of vibration in the flexible body can be described by load cases. Up to 10 load cases can be defined in the input data file. For each load case up to 10 couplings can be defined to describe the load case. If MPF is defined in the input data file and acceleration points also have been defined in the READ_RUNf-file, then automatically MCF also will be written to the message file.
MCF stands for Modal Contribution Factor, and gives information about how large amplitudes different modes of vibrations have in the acceleration points. If MCF has a big value in one direction it indicates that the ride comfort will be bad, when the actual mode of vibration is excited. MPF and MCF was introduced by Pelle Carlbom, Department of Vehicle Engineering, Royal Institute of Technology, Sweden. in his doctoral thesis Carbody and Passengers in Rail Vehicle Dynamics, TRITA-FKT2000:48, ISSN 1103-470X, ISRN KTH/FKT/D-00/48-SE.

                                                                                    
 input data parameters= lc_name*24, c_name(1), xf(1),yf(1),zf(1),ff(1),kf(1),pf(1), 
                                    c_name(2), xf(2),yf(2),zf(2),ff(2),kf(2),pf(2), 
                                     . . . . . . . . . .                            
                                     . . . . . . . . . .                            
                                    c_name(n), xf(n),yf(n),zf(n),ff(n),kf(n),pf(n)  
                                                                                    
lc_name = The name of the actual load case.
c_name(i) = Name of coupling number i which forms the load case. Maximum number of couplings are 10.
xf(i),yf(i),zf(i),ff(i),kf(i),pf(i) = The amplitudes of the load case in all 6 directions.


NODE_INTPL= c_name*12, inode1, inode2, inode3, inode4

Forces NPICK to interpolate in user defined nodes in the FEM results. The command has five arguments:
c_name = Name of the coupling or acceleration point for which the following nodes shall be used:
inode1 = Nod number 1 in the tetrahedron.
inode2 = Nod number 2 in the tetrahedron.
inode3 = Nod number 3 in the tetrahedron.
inode4 = Nod number 4 in the tetrahedron.

N.B. The nodes must form a tetrahedron in space, otherwise will program NPICK stop with an error printout.



NPICK_FILE= filename*132

Name of NPICK result file.
If NPICK_FILE is undefined, the result file will be given the name $ident.npickr.



ORIGO_CALC_FEM= x_origo, y_origo, z_origo

Distance between the origin in the CALC-model and the FEM-model. The direction of the vector should be from the CALC-model to the FEM-model. The coordinates are given in the system which arose after the rotation according to ROT_CALC_FEM.



PASS_AREA= hfloor nr_seats_x aseatf aseatl nr_seats_y bseat(1:nr_seats_y)

Defines the area where the passengers are located (if FLEX_BODY is a carbody of a vehicle). Command PASS_AREA reads the following arguments:

hfloor The height of the floor of the vehicle.
nr_seats_x Number of seats in longitudinal direction of the vehicle.
aseatf Distance from the middle of the car to the first seat.
aseatl Distance from the middle of the car to the last seat.
nr_seats_y Number of seats in lateral direction of the vehicle.
bseat(1) Lateral distance to the first seat.
bseat(2) Lateral distance to the second seat.
. . . . . . . . . . .
bseat(6) Max. 6 seats can be defined in lateral direction.

If PASS_MODEL is equal to EveryPerson or EveryPersonSeat program NPICK will generate a mesh of vertical masses modeled by 'mass m_rigid_1'. Number of vertical masses in the mesh will be (nr_seats_x * nr_seats_y).
If PASS_MODEL is equal to Condensed or CondensedSeat program NPICK will only generate one mass per mode of vibration in body FLEX_BODY. The difference in results between PASS_MODEL EveryPerson and Condensed is small because the passengers does not couple different modes of vibration to each other.



PASS_MASS= weight

The weight of all passengers (if FLEX_BODY is a carbody of a vehicle). The weight is rigid attached to the carbody in all directions except in the z-direction. In the z-direction the weight of the passengers is flexible suspended depending on the used PASS_MODEL.



PASS_MODEL= model, inputdata(*)

Type of model to be used for the passengers (if FLEX_BODY is a carbody of a vehicle). Following models are available:

EveryPerson Models every person in the carbody with a m_rigid_1-mass.
EveryPersonSeat Models every person and its seat in the carbody.
Condensed Models all passengers moving in one mode of vibration.
CondensedSeat Models all passengers and its seat moving in one mode of vibration.

The Condensed model is a way of reducing the number of degrees of freedom, in the CALC-model. The theories of the model reduction was developed by Pelle Carlbom, Department of Vehicle Engineering, Royal Institute of Technology, Sweden. in his doctoral thesis Carbody and Passengers in Rail Vehicle Dynamics, TRITA-FKT2000:48, ISSN 1103-470X, ISRN KTH/FKT/D-00/48-SE.

The different models have the following input data:

           
EveryPerson alpha, fp, zetap
alpha = PASS_MASS*alpha is the unsprung weight of the passenger
fp = The eigenfrequency of the passenger, fp=1/(2*pi)*sqrt(kp/mp). Where: kp is the internal stiffness in the passenger and mp is the total weight of the passenger.
zetap = The ratio of critical damping in the passenger, zetap=cp/2./(2*pi*fp)/mp Where: cp is the internal viscous damper in the passenger
EveryPersonSeat alpha, fp, zetap, ks, cs
alpha = PASS_MASS*alpha is the unsprung weight of the passenger
fp = The eigenfrequency of the passenger, fp=1/(2*pi)*sqrt(kp/mp). Where: kp is the internal stiffness in the passenger and mp is the total weight of the passenger.
zetap = The ratio of critical damping in the passenger, zetap=cp/2./(2*pi*fp)/mp Where: cp is the internal viscous damper in the passenger
ks = The stiffness in the seat
cs = The damping in the seat
Condensed alpha, fp, zetap
alpha = PASS_MASS*alpha is the unsprung weight of the passenger
fp = The eigenfrequency of the passenger, fp=1/(2*pi)*sqrt(kp/mp). Where: kp is the internal stiffness in the passenger and mp is the total weight of the passenger.
zetap = The ratio of critical damping in the passenger, zetap=cp/2./(2*pi*fp)/mp Where: cp is the internal viscous damper in the passenger
CondensedSeat alpha, fp, zetap, ks, cs
alpha = PASS_MASS*alpha is the unsprung weight of the passenger
fp = The eigenfrequency of the passenger, fp=1/(2*pi)*sqrt(kp/mp). Where: kp is the internal stiffness in the passenger and mp is the total weight of the passenger.
zetap = The ratio of critical damping in the passenger, zetap=cp/2./(2*pi*fp)/mp Where: cp is the internal viscous damper in the passenger
ks = The stiffness in the seat
cs = The damping in the seat


READ_RUNf= filename*132

Name of the runf-file containing the vehicle model.
From the runf-file, program NPICK reads all connection points in FLEX_BODY, where modal shapes shall be interpolated.



REL_DAMP= damp(1:100)

Fraction of critical damping of the eigenfrequencies.
The damping will be written in the file $ident'.npickr after each eigenfrequency. Default values for vector damp are 0.



ROT_CALC_FEM= Matrix (3,3)

Rotation of the coordinate system between the CALC-model and the FEM-model.
The rotation matrix rotates all vectors in the CALC-model to the FEM-model.
Example:
In the CALC-model, the z-axis points down and the y-axis points to the right. In the FEM-model, the z-axis points up and the y-axis points to the left. Then the rotation matrix shall have the following contents:

                           
  ROT_CALC_FEM = 1  0  0   
                 0 -1  0   
                 0  0 -1   
                           


FEM_XMIRROR= x_coor, iside,
xs(1), ys(1), zs(1), fs(1), ks(1), ps(1),
xs(2), ys(2), . . . etc.

Copy the FEM-model in a yz-plane.
In case the FEM-model is half and nodes only exists for positive or negative X-coordinates, the results must be copied into the other half-plane in order to generate a full model. The results can be copied in two ways: symmetric and anti-symmetric. The user must know how the boundary condition was formed in the FEM-analysis, in order to make a proper copy of the half model. The signs of the copy in the different coordinate directions are defined in the arguments: xs, ys, zs, fs, ks and ps. If xs, ys, zs, fs, ks and/or ps are set to +1 the reflection will be symmetric over the yz-plane, if xs, ys, zs, fs, ks and/or ps are set to -1 the reflection will be anti-symmetric. Program NPICK will automatically update the generalized mass due to the fact that a full model will have the double weight of the half model.

Command FEM_XMIRROR can be given in combination with the FEM_YMIRROR, in order to copy a quarter model into a full model.

The input data parameters, have the following meaning:
x_coor = Longitudinal coordinate of the yz-plane where the FEM-model ends. The coordinate should be given the the coordinate system of the FEM-model.
iside = Defines which side of the yz-plane in which the FEM-model exists.
iside = +1 indicates that the FEM-model only exists for X-coordinates bigger than x_coor.
iside = –1 indicates that the FEM-model only exists for X-coordinates less than x_coor.
xs(1) = Symmetric or anti-symmetric reflection of longitudinal displacements mod 1.
ys(1) = Symmetric or anti-symmetric reflection of lateral displacements mod 1.
zs(1) = Symmetric or anti-symmetric reflection of vertical displacements mod 1.
fs(1) = Symmetric or anti-symmetric reflection of roll displacements mod 1.
ks(1) = Symmetric or anti-symmetric reflection of pitch displacements mod 1.
ps(1) = Symmetric or anti-symmetric reflection of yaw displacements mod 1.
xs(2) = Symmetric or anti-symmetric reflection of longitudinal displacements mod 2.
ys(2) = Symmetric or anti-symmetric reflection of lateral displacements mod 2.
zs(2) = Symmetric or anti-symmetric reflection of vertical displacements mod 2.
fs(2) = etc. until ps(nform) where nform is the number of the last eigenmode defined in command FEM_RES_FILE.

The vectors xs-ps for all eigenmodes must be defined, otherwise will program NPICK stop with an error printout.



FEM_YMIRROR= y_coor, iside,
xs(1), ys(1), zs(1), fs(1), ks(1), ps(1),
xs(2), ys(2), . . . etc.

Copy the FEM-model in a yz-plane.
In case the FEM-model is half and nodes only exists for positive or negative Y-coordinates, the results must be copied into the other half-plane in order to generate a full model. The results can be copied in two ways: symmetric and anti-symmetric. The user must know how the boundary condition was formed in the FEM-analysis, in order to make a proper copy of the half model. The signs of the copy in the different coordinate directions are defined in the arguments: xs, ys, zs, fs, ks and ps. If xs, ys, zs, fs, ks and/or ps are set to +1 the reflection will be symmetric over the yz-plane, if xs, ys, zs, fs, ks and/or ps are set to -1 the reflection will be anti-symmetric. Program NPICK will automatically update the generalized mass due to the fact that a full model will have the double weight of the half model.

Command FEM_YMIRROR can be given in combination with the FEM_XMIRROR, in order to copy a quarter model into a full model.

The input data parameters, have the following meaning:
y_coor = Longitudinal coordinate of the yz-plane where the FEM-model ends. The coordinate should be given the the coordinate system of the FEM-model.
iside = Defines which side of the yz-plane in which the FEM-model exists.
iside = +1 indicates that the FEM-model only exists for Y-coordinates bigger than y_coor.
iside = –1 indicates that the FEM-model only exists for Y-coordinates less than y_coor.
xs(1) = Symmetric or anti-symmetric reflection of longitudinal displacements mod 1.
ys(1) = Symmetric or anti-symmetric reflection of lateral displacements mod 1.
zs(1) = Symmetric or anti-symmetric reflection of vertical displacements mod 1.
fs(1) = Symmetric or anti-symmetric reflection of roll displacements mod 1.
ks(1) = Symmetric or anti-symmetric reflection of pitch displacements mod 1.
ps(1) = Symmetric or anti-symmetric reflection of yaw displacements mod 1.
xs(2) = Symmetric or anti-symmetric reflection of longitudinal displacements mod 2.
ys(2) = Symmetric or anti-symmetric reflection of lateral displacements mod 2.
zs(2) = Symmetric or anti-symmetric reflection of vertical displacements mod 2.
fs(2) = etc. until ps(nform) where nform is the number of the last eigenmode defined in command FEM_RES_FILE.

The vectors xs-ps for all eigenmodes must be defined, otherwise will program NPICK stop with an error printout.



SCALE_CALC_FEM= s_fact

Scale factor between the CALC-model and the FEM-model. The CALC-model coordinates will be multiplied with factor s_fact before interpolation in the FEM-model takes place. If the FEM-model has been modeled in millimeters and metric tonnes, the value of s_fact should be set to 1000. Default value of s_fact is equal to 1.



STOP
                        
 STOP                   
                        

Stops further input data reading.
The command can be used when the user wishes to interrupt reading the input data file at a certain point.



TOL_NODE_DMIN
                        
 TOL_NODE_DMIN= eps     
                        

Sets the node min distance selection tolerance.
Program NPICK will search for nodes forming a tetrahedron around the point in body FLEX_BODY. The distances between the nodes around the point must be separated with a distance of at least eps.

Declared Real*4   Default= 1.e-4



TOL_NODE_DMAX
                        
 TOL_NODE_DMAX= eps     
                        

Sets the node max distance selection tolerance.
Program NPICK will not search for nodes having a distance more than eps from the point in body FLEX_BODY. If program NPICK not can find four nodes within eps, an error will occur and further execution will be stopped.

Declared Real*4   Default= 0.2



TOL_NODE_LMIN
                        
 TOL_NODE_LMIN= eps     
                        

Sets the min value of the shape functions of the tetrahedron.
Program NPICK calculates two types of shape functions of the tetrahedron: sf_1 and sf_2. The value of sf_1 is calculated as the distance between node 3 and the line through node 1 and 2, divided by the distance between node 1 and 2. The value of sf_2 is calculated as the distance between node 4 and the plane formed by the nodes 1, 2 and 3. Program NPICK will not use nodes, which makes the shape functions less than eps.

Declared Real*4   Default= 0.05



TOL_NODE_LMAX
                        
 TOL_NODE_LMAX= eps     
                        

Sets the max value of the shape functions of the tetrahedron.
Program NPICK calculates two types of shape functions of the tetrahedron: sf_1 and sf_2. The value of sf_1 is calculated as the distance between node 3 and the line through node 1 and 2, divided by the distance between node 1 and 2. The value of sf_2 is calculated as the distance between node 4 and the plane formed by the nodes 1, 2 and 3. Program NPICK will not use nodes, which makes the shape functions greater than eps.

Declared Real*4   Default= 20.



Command line options


For program NPICK a number of command line options are available. The user can put his or hers favorite options in a file named .gen_conf. Program NPICK searches primarily for the .gen_conf-file in the local working directory. If the file not can be found in the local working directory, program NPICK searches for the .gen_conf-file in the users home-directory. At last if no .gen_conf-file can be found program NPICK reads the file $gensys/bin/gen_conf. Following options are understood:

-addarg = Prompt for more arguments before calculation starts
-batch = Prepare an expanded input data file for later use
-debug = Don't remove temporary work files after execution
-help = Print this help information
-overwrite = Overwrite old results without questions.
-qident = Ask for an ident before starting the execution
-qread_runf = Ask if a new input data file shall be opened in an editor before execution.
-qshort = Run calculation in the short queue.
     
arg(1) = Inputdatafile
arg(2) = Ident

All of the above options can be given with the prefix no_. If the prefix no_ has been given, the opposite meaning of the option will apply.



File formats


File formats from the NPICK program

Program NPICK generates three different result files:

  1. NPICK Result File with extension '.npickr'
    File .npickr is the file which shall be inserted in the CALC input data file. The insertion point in the runf-file, must be after that the rigid mass and all its couplings and acceleration points have been defined.

  2. NPICK Message File with extension '.npickm'
    File .npickm is a message file showing the user how program NPICK has treated the FEM results. All coordinates in both coordinate systems are listed, node numbers are listed, weighting factors are listed, etc. all for the users information.

  3. NPICK Interpolation File .npicki contains nod numbers in the FEM-model, if the user wants to use the same set of nodes as in an earlier calculation. Just insert this file in the next NPICK activity with the INSERT-command.



File formats from the FEM program

File formats from Patran

In the Patran pre- and post- processor, the geometry of the FEM-model is defined in a file named "Patran Neutral File" and the mode shapes are written to files named "Patran Nodal Displacement Results Files"

The Patran Neutral File shall be written in the following format:
                                                                                 
   Record  Contents                             Format         Note              
     1     25, ID, IV, KC                       (i2,8i8)                         
     2     TITLE                                (20a4)                           
     3     26, ID, IV, KC, N1, N2, N3, N4, N5   (i2,8i8)       N1=number of nodes
     4     DATE, TIME, VERSION                  (3a4,2a4,3a4)                    
                                                                                 
     5     1, ID, IV, KC                        (i2,8i8)                         
     6     X, Y, Z                              (3e16.9)                         
     7     ICF, GTYPE, NDF, CONFIG, CID, PSPC   (i1,1a1,3i8,2x,6i1)              
     .     .                                     .                               
     .     .                                     .                               
     .     .                                     .                               
 (3*N1+4)  ICF, GTYPE, NDF, CONFIG, CID, PSPC   (i1,1a1,3i8,2x,6i1)              
                                                                                 
    All other records are skipped by NPICK                                       
                                                                                 
                                                                                 

The Patran Nodal Displacement Results File shall be written in the following format:
                                                                                 
   Record  Contents                              Format                          
     1     TITLE                                 (80a1)                          
     2     NNODES, MAXNOD, DEFMAX, NDMAX, NWIDTH (2i9,e15.6,2i9)                 
     3     SUBTITLE 1                            (80a1)                          
     4     SUBTITLE 2                            (80a1)                          
     5     NODID, (DATA(J),J=1,6)                (i8, (6e13.7))                  
     .     .                                      .                              
     .     .                                      .                              
  N1+4     NODID, (DATA(J),J=1,6)                (i8, (6e13.7))                  
                                                                                 
                                                                                 
   SUBTITLE 2 may contain the following two commands and information:            
                                                                                 
   Command     Value            Note                                             
   FREQUENCY = freq             Eigenfrequency                                   
   GEN.MASS. = mg               Generalized mass      mg= xT M x                 
                                                                                 
                                                                                 
   If command FREQUENCY is lacking in the file, program NPICK will write an      
   eigenfrequency of  0. [Hz] in the result file $ident.npickr.                  
                                                                                 
   If command GEN.MASS. is lacking in the file, program NPICK will assume that   
   the mode shapes are mass orthonormalized.                                     
                                                                                 

Number of nodes and their numbers must agree between "Patran Neutral File" and "Patran Nodal Displacement Results File", otherwise will the result be sorted in wrong order.



Example 1:  Master input data file for program NPICK

#                                                                               
# HEAD 1 "Head #1 is read from Patran Neutral File"                             
  HEAD 2 "CALC input data are read from file runf/Master.runf"                  
  HEAD 3 "Test of program NPICK"                                                
                                                                                
#                                                                               
# Read input data file for program CALC                                         
# -------------------------------------                                         
  READ_RUNf= 'runf/Master.runf'                                                 
  FLEX_BODY= 'car_1'                                                            
#                                                                               
                                                                                
#                                                                               
# Read result data files from FEM-calculations                                  
# -------------------------------------------                                   
  FEM_GEOM_FILE patran 'ver_data/patran.out.1'                                  
  FEM_RES_FILE  patran 'ver_data/plat_m7'                                       
                       'ver_data/plat_m8'                                       
                       'ver_data/plat_m9'                                       
                                                                                
#                                                                               
# Set tolerances for the node selection                                         
# -------------------------------------------                                   
  TOL_NODE_DMIN= 0.0001 # Min distance between the nodes in the tetrahedron     
  TOL_NODE_DMAX= 0.200  # Max distance to a node in the tetrahedron             
  TOL_NODE_LMIN= 0.05   # Min value of the shape function                       
  TOL_NODE_LMAX= 20.    # Max value of the shape function                       
                                                                                
#                                                                               
# Set viscous damping of the free-free vibration modes of body                  
# defined in FLEX_BODY. The amount of damping is given as ratio                 
# to critical damping.                                                          
# ---------------------------------------------                                 
  REL_DAMP=  0.012, 0.015, 0.019                                                
                                                                                
#                                                                               
# Orient the CALC coordinate system into the                                    
# FEM coordinate system                                                         
# ------------------------------------------------------------------            
# The rotation is made according to: v(FEM) = ROT_CALC_FEM * v(CALC)            
# Where: v(CALC)      = Vector in the input data model for program CALC.        
#        ROT_CALC_FEM = The matrix of rotation.                                 
#        v(FEM)       = Vector in the FEM program.                              
# ------------------------------------------------------------------            
  ROT_CALC_FEM=  1  0  0                                                        
                 0 -1  0                                                        
                 0  0 -1                                                        
                                                                                
#                                                                               
# Distance from the rotated CALC coordinate system into the                     
# FEM coordinate system                                                         
# ----------------------------------------------------------                    
  ORIGO_CALC_FEM= -6., -2., 1.04                                                
# ORIGO_CALC_FEM= -6.,  0., 1.04                                                
                                                                                
#                                                                               
# Scale factor between the CALC coordinate system and the                       
# FEM coordinate system                                                         
# --------------------------------------------------------                      
  SCALE_CALC_FEM= 1000.,        # In FEM model: lengths are in [mm]             
                                # and masses are in [metric tons]               
  SCALE_CALC_FEM= 1.,           # In FEM model: lengths are in [m]              
                                # and masses are in [kg]                        
                                                                                
#                                                                               
# Define a load cases for calculation of Modal Participation Factor             
# -----------------------------------------------------------------             
#                                                                               
  MPF 1st_Zbending   kzkb11h       0,0, 1,0,0,0,                                
                     kzkb11v       0,0, 1,0,0,0,                                
                     kzkb12h       0,0, 1,0,0,0,                                
                     kzkb12v       0,0, 1,0,0,0,                                
  MPF 2nd_Zbending   kzkb11h       0,0, 1,0,0,0,                                
                     kzkb11v       0,0, 1,0,0,0,                                
                     kzkb12h       0,0,-1,0,0,0,                                
                     kzkb12v       0,0,-1,0,0,0,                                
  MPF 1st_Ybending   kzkb11h       0, 1,0,0,0,0,                                
                     kzkb11v       0, 1,0,0,0,0,                                
                     kzkb12h       0, 1,0,0,0,0,                                
                     kzkb12v       0, 1,0,0,0,0,                                
  MPF 2nd_Ybending   kzkb11h       0, 1,0,0,0,0,                                
                     kzkb11v       0, 1,0,0,0,0,                                
                     kzkb12h       0,-1,0,0,0,0,                                
                     kzkb12v       0,-1,0,0,0,0,                                
  MPF torsion        kzkb11h       0,0, 1,0,0,0,                                
                     kzkb11v       0,0,-1,0,0,0,                                
                     kzkb12h       0,0,-1,0,0,0,                                
                     kzkb12v       0,0, 1,0,0,0,                                
                                                                                
#                                                                               
# Force NPICK to use predefined nodes in the FEM-model for                      
# the coupling mentioned below.                                                 
# -----------------------------------------------------------                   
    NODE_INTPL= kzkb11h  32 20 19 54                                            
    NODE_INTPL= kzkb11v  32 20 19 54                                            
    NODE_INTPL= kzkb12h   1 14  2 54                                            
    NODE_INTPL= kzkb12v   1 14  2 54                                            
                                                                                
#                                                                               
# Or if a *.npicki-file has been generated earlier the input                    
# data reading can be redirected to file np_ident.npicki in order               
# to read the commands NODE_INTPL from a previous calculation.                  
# -----------------------------------------------------------                   
# INSERT np_ident.npicki                                                        
                                                                                
#                                                                               
#                                                                               
# Passenger load                                                                
# -------------------------------------------                                   
  PASS_MASS = 7000                                                              
#                             alpha, fp, zetap,   ks,  cs                       
# PASS_MODEL= EveryPerson,      0.1, 5.,  0.5                                   
# PASS_MODEL= EveryPersonSeat,  0.1, 5.,  0.5,   110e3, 2200                    
  PASS_MODEL= Condensed,        0.1, 5.,  0.5                                   
# PASS_MODEL= CondensedSeat,    0.1, 5.,  0.5,   4.4e6, 88e3                    
#                                                                               
#             h   nr.seats +a   -a    nr.rows  b1  b2                           
  PASS_AREA= -1.4   20      6.  -6.     2      1. -1.                           
                                                                                
#                                                                               
#                                                                               
# Define mirror planes if the carbody in the                                    
# FEM model is only a half or a quarter of a body.                              
# The six number at the end guides NPICK how to reflect the modal shapes.       
# -----------------------------------------------------------------------       
# FEM_XMIRROR= 6.,   # X coordinate for the mirror yz-plane                     
#             +1,    # The FEM-model exists for positive coordinates            
#             -1 +1 +1  +1 -1 -1  # First bending mode; symmetric reflection    
#             +1 -1 -1  -1 +1 +1  # Torsion mode; anti-symmetric reflection     
#             -1 +1 +1  +1 -1 -1  # Second bending mode; symmetric reflection   
#                                                                               
# FEM_YMIRROR= 2.,   # Y coordinate for the mirror xz-plane                     
#             +1,    # The FEM-model exists for positive coordinates            
#             +1 -1 +1  -1 +1 -1  # First bending mode; symmetric reflection    
#             -1 +1 -1  +1 -1 +1  # Torsion mode; anti-symmetric reflection     
#             +1 -1 +1  -1 +1 -1  # Second bending mode; symmetric reflection   



Example 2:  Create a npick result file manually

Following example shows how to manually create a torsional vibration mode of a wheelset: npick/Wheelset_torsion_vibration.pdf




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