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### `mass` = `m_type`, input(*)

Definition of a mass.
If a new body is created, and the new body has the same name as a previous body, the first body cannot be overwritten, as different masses require different amounts of space in the main memory. Therefore, the first defined body is the valid mass, and the second body will be ignored.

First a brief summary is given of the available subcommands in mass, followed by a detailed description of each subcommand.

 `fixpoint_6` Creates a mass with constraints in all directions. `m_flex_1` Defines flexible mode shapes to a rigid body `m_rigid_1` Creates a mass with 1 degree of freedoms `m_rigid_12` Creates a mass with 6 degree of freedoms. Equation of motions in a body fixed frame `m_rigid_6` Creates a mass with 6 degrees of freedoms `m_rigid_6f` Creates a mass without inertia acceleration. `m_rigid_36b` Creates a body with 6 degrees of freedoms, with body-fixed equations of motion `massless1` Creates a mass without mass-matrix, only for stiffness couplings `massless13` Creates a mass without mass-matrix, handles both stiffnesses and dampers The tolerance of the positioning of the massless mass is on unbalanced force. `massless13p` Creates a mass without mass-matrix, handles both stiffnesses and dampers. The tolerance of the positioning of the massless mass is on unbalanced position. `massless14` Creates a one-dimensional mass without mass-matrix, handles both stiffnesses and dampers The tolerance of the positioning of the massless mass is on unbalanced force. `massless2` Creates a mass without mass-matrix, handles both stiffnesses and dampers, must have dampers

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#### m_type = `fixpoint_6`

Creates a mass with 6 directions, however these directions have no degrees of freedom as all movements are constricted. Therefore, no data regarding the mass matrix is necessary. The user can still move the mass defined in command fixpoint_6, by using simple func-commands which will overwrite the variables generated in the fixpoint_6-command.

```
mass fixpoint_6  `m_name' `lsys' (+-`)acg (+-`)bcg (+-`)hcg

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys.

Generated variables in the main memory of the program:

Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis). m_name.vx = Displacement velocity of the center of gravity in x-direction. m_name.vy = Displacement velocity of the center of gravity in y-direction. m_name.vz = Displacement velocity of the center of gravity in z-direction. m_name.vf = Displacement velocity in f-direction. m_name.vk = Displacement velocity in k-direction. m_name.vp = Displacement velocity in p-direction.
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#### m_type = `m_flex_1`

Defines a flexible body.
Before this command can be given, a rigid mass must have been defined previously in the input data, by command "mass m_rigid_6" or "mass m_rigid_36b". For every eigenfrequency which is given in this command, two equations of motion are added to the total number of equations in the input data model. The new equations are expressed in so-called generalized coordinates and are excited by generalized forces, which will be defined in command "coupl m_flex_1". Input of the input data is ended when new valid main command according to Input data main-commands is given.

```
mass m_flex_1 `m_name' (+-`)fq1 (+-`)damp1 (+-`)fq2 (+-`)damp2 (+-`)fq3 ,,,  (+-`)fq(n) (+-`)damp(n)

```
 m_name = Name of the created mass. fq1 = Eigenfrequency number 1, defined in [Hz]. damp1 = Relative damping number 1, defined in fraction of critical damping. fq2,damp2 = Eigenfrequency and damping number 2. . . . . = . . . . . . . . . . . . . . . . . . . . . = . . . . . . . . . . . . . . . . . fq(n),damp(n) = Eigenfrequency and damping number n.

Variables generated in main memory:

Input variables:
 m_name.f1 = Eigenfrequency number 1 m_name.f2 = Eigenfrequency number 2 . . . . = . . . . . . . . . . . . . . . . . m_name.fn = Eigenfrequency number n m_name.d1 = Relative damping number 1 m_name.d2 = Relative damping number 2 . . . . = . . . . . . . . . . . . . . . . . m_name.dn = Relative damping number n

Output variables:
 m_name.c1 = The generalized coordinate's position for eigenfrequency 1 m_name.c2 = The generalized coordinate's position for eigenfrequency 2 . . . . = . . . . . . . . . . . . . . . . . m_name.cn = The generalized coordinate's position for eigenfrequency n m_name.v1 = The generalized coordinate's velocity for eigenfrequency 1 m_name.v2 = The generalized coordinate's velocity for eigenfrequency 2 . . . . = . . . . . . . . . . . . . . . . . m_name.vn = The generalized coordinate's velocity for eigenfrequency n m_name.a1 = The generalized coordinate's acceleration for eigenfrequency 1 m_name.a2 = The generalized coordinate's acceleration for eigenfrequency 2 . . . . = . . . . . . . . . . . . . . . . . m_name.an = The generalized coordinate's acceleration for eigenfrequency n m_name.F1 = The total generalized force acting on eigenfrequency 1 m_name.F2 = The total generalized force acting on eigenfrequency 2 . . . . = . . . . . . . . . . . . . . . . . m_name.Fn = The total generalized force acting on eigenfrequency n

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#### m_type = `m_rigid_1`

Creates a rigid mass with 1 degree of freedom.

```
mass m_rigid_1 `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg  (+-`)m_data `dire`

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. m_data = The value of the mass dire = Coordinate direction in which the mass can move. Valid directions are x, y, z, f, k and p.

Generated variables in the main memory of the program:

Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction. m_name.xx = The mass, if dire= x. m_name.yy = The mass, if dire= y. m_name.zz = The mass, if dire= z. m_name.ff = The mass, if dire= f. m_name.kk = The mass, if dire= k. m_name.pp = The mass, if dire= p.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis). m_name.vx = Displacement velocity of the center of gravity in x-direction. m_name.vy = Displacement velocity of the center of gravity in y-direction. m_name.vz = Displacement velocity of the center of gravity in z-direction. m_name.vf = Displacement velocity in f-direction. m_name.vk = Displacement velocity in k-direction. m_name.vp = Displacement velocity in p-direction. m_name.Fx = The sum of forces in x-direction acting on the center of gravity. m_name.Fy = The sum of forces in y-direction acting on the center of gravity. m_name.Fz = The sum of forces in z-direction acting on the center of gravity. m_name.Mf = The sum of the moments in the f-direction acting on the center of gravity. m_name.Mk = The sum of the moments in the k-direction acting on the center of gravity. m_name.Mp = The sum of the moments in the p-direction acting on the center of gravity. m_name.Ax = Inertia acceleration in the x-direction acting on the body, due to moving coordinate systems. m_name.Ay = Inertia acceleration in the y-direction acting on the body, due to moving coordinate systems. m_name.Az = Inertia acceleration in the z-direction acting on the body, due to moving coordinate systems. m_name.Af = Inertia acceleration in f-direction acting on the body, due to moving coordinate systems. m_name.Ak = Inertia acceleration in k-direction acting on the body, due to moving coordinate systems. m_name.Ap = Inertia acceleration in p-direction acting on the body, due to moving coordinate systems.

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#### m_type = `m_rigid_12`

Creates a rigid mass with 6 degrees of freedoms.
The equation of motion are setup in a body fixed coordinate system.

```  mass  m_rigid_12   m_name   `lsys'   (+-`)acg (+-`)bcg (+-`)hcg
mx       my       mz
Jff      Jfk      Jfp
Jkf      Jkk      Jkp
Jpf      Jpk      Jpp
```
 m_name = Name of the created mass lsys = Name of the local coordinate system which the body relates to acg = Center of gravity, longitudinal position in relation to lsys bcg = Center of gravity, lateral position in relation to lsys hcg = Center of gravity, vertical position in relation to lsys mx = The mass in the x-direction my = The mass in the y-direction mz = The mass in the z-direction Jff = Moment of inertia    Σ mk · ( yk2 + zk2 ) Jkk = Moment of inertia    Σ mk · ( xk2 + zk2 ) Jpp = Moment of inertia    Σ mk · ( xk2 + yk2 ) Jfk = Jkf = Product of inertia   -Σ mk xk yk Jfp = Jpf = Product of inertia   -Σ mk xk zk Jkp = Jpk = Product of inertia   -Σ mk yk zk

Generated variables in the main memory of the program:

Input variables:
mvh
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction. m_name.xx = The mass in the x-direction m_name.yy = The mass in the y-direction m_name.zz = The mass in the z-direction m_name.ff = Matrix component Jff m_name.fk = Matrix component Jfk m_name.fp = Matrix component Jfp m_name.kf = Matrix component Jkf m_name.kk = Matrix component Jkk m_name.kp = Matrix component Jkp m_name.pf = Matrix component Jpf m_name.pk = Matrix component Jpk m_name.pp = Matrix component Jpp

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis). m_name.vx = Displacement velocity of the center of gravity in x-direction. m_name.vy = Displacement velocity of the center of gravity in y-direction. m_name.vz = Displacement velocity of the center of gravity in z-direction. m_name.vf = Displacement velocity in f-direction. m_name.vk = Displacement velocity in k-direction. m_name.vp = Displacement velocity in p-direction. m_name.Fx = The sum of forces in x-direction acting on the center of gravity. m_name.Fy = The sum of forces in y-direction acting on the center of gravity. m_name.Fz = The sum of forces in z-direction acting on the center of gravity. m_name.Mf = The sum of the moments in the f-direction acting on the center of gravity. m_name.Mk = The sum of the moments in the k-direction acting on the center of gravity. m_name.Mp = The sum of the moments in the p-direction acting on the center of gravity. m_name.Fxb = Force m_name.Fx in a body fixed coordinate system m_name.Fyb = Force m_name.Fy in a body fixed coordinate system m_name.Fzb = Force m_name.Fz in a body fixed coordinate system m_name.Mfb = Force m_name.Mf in a body fixed coordinate system m_name.Mkb = Force m_name.Mk in a body fixed coordinate system m_name.Mpb = Force m_name.Mp in a body fixed coordinate system m_name.11 = Rotation matrix from fsys to the body component 11 m_name.12 = Rotation matrix from fsys to the body component 12 m_name.13 = Rotation matrix from fsys to the body component 13 m_name.21 = Rotation matrix from fsys to the body component 21 m_name.22 = Rotation matrix from fsys to the body component 22 m_name.23 = Rotation matrix from fsys to the body component 23 m_name.31 = Rotation matrix from fsys to the body component 31 m_name.32 = Rotation matrix from fsys to the body component 32 m_name.33 = Rotation matrix from fsys to the body component 33

Usage:
 – Modeling of masses that not are bound by rails – Road vehicles

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#### m_type = `m_rigid_6`

Creates a mass with 6 degrees of freedoms.
In input data only the diagonal of the mass matrix of the mass, will be read.

```
mass m_rigid_6  `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg  (+-`)m_diag

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. m_diag = The diagonal of the mass matrix, comprising the values: mx,my,mz,Jfi,Jchi,Jpsi

Generated variables in the main memory of the program:

Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction. m_name.xx = The mass matrix' value for the component (1,1). m_name.xy = The mass matrix' value for the component (1,2). m_name.xz = The mass matrix' value for the component (1,3). m_name.xf = The mass matrix' value for the component (1,4). m_name.xk = The mass matrix' value for the component (1,5). m_name.xp = The mass matrix' value for the component (1,6). m_name.yx = The mass matrix' value for the component (2,1). m_name.yy = The mass matrix' value for the component (2,2). . . . . = . . . . . . . . . . . . . . . . . . . . . = . . . . . . . . . . . . . . . . . m_name.pp = The mass matrix' value for the component (6,6).

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis). m_name.vx = Displacement velocity of the center of gravity in x-direction. m_name.vy = Displacement velocity of the center of gravity in y-direction. m_name.vz = Displacement velocity of the center of gravity in z-direction. m_name.vf = Displacement velocity in f-direction. m_name.vk = Displacement velocity in k-direction. m_name.vp = Displacement velocity in p-direction. m_name.Fx = The sum of forces in x-direction acting on the center of gravity. m_name.Fy = The sum of forces in y-direction acting on the center of gravity. m_name.Fz = The sum of forces in z-direction acting on the center of gravity. m_name.Mf = The sum of the moments in the f-direction acting on the center of gravity. m_name.Mk = The sum of the moments in the k-direction acting on the center of gravity. m_name.Mp = The sum of the moments in the p-direction acting on the center of gravity. m_name.Ax = Inertia acceleration in the x-direction acting on the body, due to moving coordinate systems. m_name.Ay = Inertia acceleration in the y-direction acting on the body, due to moving coordinate systems. m_name.Az = Inertia acceleration in the z-direction acting on the body, due to moving coordinate systems. m_name.Af = Inertia acceleration in f-direction acting on the body, due to moving coordinate systems. m_name.Ak = Inertia acceleration in k-direction acting on the body, due to moving coordinate systems. m_name.Ap = Inertia acceleration in p-direction acting on the body, due to moving coordinate systems.

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#### m_type = `m_rigid_6f`

Creates a mass without inertia acceleration.
In input data only the diagonal of the mass matrix of the mass, will be read. This type of mass is similar to the m_rigid_6-type of mass, except that m_rigid_6f has no inertia acceleration due to accelerating coordinate systems.

```
mass m_rigid_6f  `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg  (+-`)m_diag

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. m_diag = The diagonal of the mass matrix, comprising the values:mx,my,mz,Jfi,Jchi,Jpsi

Generated variables in the main memory of the program:

Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction. m_name.xx = The mass matrix' value for the component (1,1). m_name.xy = The mass matrix' value for the component (1,2). m_name.xz = The mass matrix' value for the component (1,3). m_name.xf = The mass matrix' value for the component (1,4). m_name.xk = The mass matrix' value for the component (1,5). m_name.xp = The mass matrix' value for the component (1,6). m_name.yx = The mass matrix' value for the component (2,1). m_name.yy = The mass matrix' value for the component (2,2). . . . . = . . . . . . . . . . . . . . . . . . . . . = . . . . . . . . . . . . . . . . . m_name.pp = The mass matrix' value for the component (6,6).

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis). m_name.vx = Displacement velocity of the center of gravity in x-direction. m_name.vy = Displacement velocity of the center of gravity in y-direction. m_name.vz = Displacement velocity of the center of gravity in z-direction. m_name.vf = Displacement velocity in f-direction. m_name.vk = Displacement velocity in k-direction. m_name.vp = Displacement velocity in p-direction. m_name.Fx = The sum of forces in x-direction acting on the center of gravity. m_name.Fy = The sum of forces in y-direction acting on the center of gravity. m_name.Fz = The sum of forces in z-direction acting on the center of gravity. m_name.Mf = The sum of the moments in the f-direction acting on the center of gravity. m_name.Mk = The sum of the moments in the k-direction acting on the center of gravity. m_name.Mp = The sum of the moments in the p-direction acting on the center of gravity.

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#### m_type = `m_rigid_36b`

Creates a body with 6 degrees of freedoms.
The equations of motion are set up in a body-fixed coordinate system. As input data, the entire local mass matrix is given.

```
mass m_rigid_36b  `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg  (+-`)m_mat

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. m_mat = The local mass matrix, comprising the values: ``` mxx, mxy, mxz, mxf, mxk, mxp, myx, myy, myz, myf, myk, myp, mzx, mzy, mzz, mzf, mzk, mzp, mfx, mfy, mfz, mff, mfk, mfp, mkx, mky, mkz, mkf, mkk, mkp, mpx, mpy, mpz, mpf, mpk, mpp ``` The lower right quadrant of the mass matrix, defines the moment of inertia tensor. The mass matrix can be read in as variables, but the variables' value is only read at the beginning of the calculation. The values, which the variables have at the beginning of the calculation, are assigned to the mass matrix, which are then constant during the course of the calculation.

The variables generated in main memory are the same as for m_rigid_6.

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#### m_type = `massless1`

Creates a mass without mass matrix, with the possibilities of motion in all coordinate directions. The mass only accepts connected couplings of type stiffnesses. Couplings with viscous damping of type c and kc are not accepted by massless1. On definition of massless1, the surrounding masses are also checked to ensure that they are of "m_rigid_6" or "m_rigid_36b" type bodies, where the positions are integrated.

```
mass massless1  `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg
r_linj  r_feps  m_loop

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. r_linj = The linearization step which the solution will use for the adjustment of the position of the point. r_feps = The force tolerance which the total force on the massless point must meet at every integration step. m_loop = Max. number of iteration loops before the calculation is interrupted. If the massless point's remaining force has not meet the tolerance r_feps within m_loop number of loops, the calculations will be interrupted in the program CALC.

Variables generated in the main memory:
Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis).

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#### m_type = `massless12`

Mass type massless12 only exists for compatibility reasons. Please use mass type massless13 instead.

#### m_type = `massless12p`

Mass type massless12p only exists for compatibility reasons. Please use mass type massless13p instead.

#### m_type = `massless13`

Creates a mass without mass matrix, with the possibilities of motion in all coordinate directions.
The body accepts k, c, and kc type couplings linked to it. On definition of massless13, the surrounding masses are also checked to ensure that they are of "m_rigid_6" or "m_rigid_36b" type bodies, where the positions are integrated.

```
mass massless13  `m_name' `lsys' (+-`)acg (+-`)bcg (+-`)hcg
r_linj  r_feps  m_loop

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. r_linj = The linearization step which the solution will use for the adjustment of the position of the point. r_feps = The force tolerance which the total force on the massless point must meet at every integration step. m_loop = Max. number of iteration loops before the calculation is interrupted. If the massless point's remaining force has not meet the tolerance r_feps within m_loop number of loops, the calculations will be interrupted in the program CALC.

Variables generated in the main memory:
Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis).

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#### m_type = `massless13p`

Creates a mass without mass matrix, with the possibilities of motion in all coordinate directions.
The body accepts k, c and kc type couplings linked to it. On definition of massless13p, the surrounding masses are also checked to ensure that they are of m_rigid_6 or m_rigid_36b type bodies, where the positions are integrated. The difference between massless13 and massless13p, is that the tolerance r_feps is given in unbalanced position instead of unbalanced force as in massless13 above.

```
mass massless13p  `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg
r_linj  r_feps  m_loop

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. r_linj = Amplitude which will be used for linearization of stiffnesses and dampers attached to the mass. r_feps = Position tolerance which must be fulfilled in every integration step. m_loop = Max. number of iteration loops before the calculation will be interrupted.

Variables generated in the main memory:
Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis).

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#### m_type = `massless14`

Creates a one-dimensional mass without mass matrix.
In other directions the mass is connected to another mass having six degrees of freedom.

```
mass massless14  `m_name' `lsys' (+-`)acg (+-`)bcg (+-`)hcg
r_linj  r_feps  m_loop
dire    mass2

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys. r_linj = The linearization step which the solution will use for the adjustment of the position of the point. r_feps = The force tolerance which the total force on the massless point must meet at every integration step. m_loop = Max. number of iteration loops before the calculation is interrupted. If the massless point's remaining force has not meet the tolerance r_feps within m_loop number of loops, the calculations will be interrupted in the program CALC. dire = The free direction of the mass. Valid directions are x,y,z,f,k and p. /td> mass2 = The mass to be followed in other directions. /td>

Variables generated in the main memory:
Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis).

 m_name.vx = Velocity of the center of gravity in x-direction. m_name.vy = Velocity of the center of gravity in y-direction. m_name.vz = Velocity of the center of gravity in z-direction. m_name.vf = Velocity in f-direction (rotation around the x-axis). m_name.vk = Velocity in k-direction (rotation around the y-axis). m_name.vp = Velocity in p-direction (rotation around the z-axis).

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#### m_type = `massless2`

Creates a mass without mass matrix, with the possibilities of motion in all coordinate directions.
The body only accepts k or c type couplings linked to it. The body's position is integrated by differential equation of the first order. Massless2, therefore, requires that at least one viscous coupling is connected in every coordinate direction. Should there not be a viscous coupling in a certain direction, the direction must have constraints. The eigenvalue for the massless point can be calculated according to the following equation:
$\omega =\frac{k}{c}$
The equation shows that the system will have a high eigenfrequency if the stiffness is high and the damping low.

```
mass massless2 `m_name' `lsys'  (+-`)acg (+-`)bcg (+-`)hcg

```
 m_name = Name of the created mass. lsys = Name of the local coordinate system which the body relates to. acg,bcg,hcg = The body's center of gravity in relation to lsys.

Variables generated in the main memory:
Input variables:
 m_name.a = Distance lsys to the body's center of gravity in x-direction. m_name.b = Distance lsys to the body's center of gravity in y-direction. m_name.h = Distance lsys to the body's center of gravity in z-direction.

Output variables:
 m_name.x = Displacement of the center of gravity in x-direction. m_name.y = Displacement of the center of gravity in y-direction. m_name.z = Displacement of the center of gravity in z-direction. m_name.f = Displacement in f-direction (rotation around the x-axis). m_name.k = Displacement in k-direction (rotation around the y-axis). m_name.p = Displacement in p-direction (rotation around the z-axis).

Reference Manuals   Calc menu   Input Data Menu