To define a bushing, you need to create two markers, one for each part. The marker on the first part that you specify is called the I marker. The marker on the second part that you specify is called the J marker.

Learn about Constitutive Equations for Bushings.

The following procedure modifies the following for a Bushing:

Learn about Constitutive Equations for Bushings.

The following constitutive equations define how Adams View uses the data for a linear Bushing to apply a force and a torque to the action body depending on the displacement and velocity of the I marker on the action body relative to the J marker on the reaction body.

where:

The bushing element applies an equilibrating force and torque to the J marker in the following way:

where:

For the rotational constitutive equations to be accurate, at least two of the rotations (a, b, c) must be small. That is, two of the three values must remain smaller than 10 degrees. In addition, if a becomes greater than 90 degrees, b becomes erratic. If b becomes greater than 90 degrees, a becomes erratic. Only c can become greater than 90 degrees without causing convergence problems. For these reasons, it is best to define your bushing such that angles a and b remain small (not a and c and not b and c).

Advanced bushing supports two modeling methods.

To define a bushing, you need to create two markers, one for each part. The marker on the first part that you specify is called the I marker. The marker on the second part that you specify is called the J marker.

The following procedure modifies the following for a Bushing:

 

To learn about bushings click on the below links.

A translational spring damper represents forces acting between two parts over a distance and along a particular direction. You specify the locations of the spring damper and points on two parts. Adams View calculates the spring and damping forces based on the distance between the locations on the two parts and their rate of change, respectively.

It applies an action force to the first part you select, called the action body, and applies an equal and opposite reaction force to the second part you select, called the reaction body. The forces are both directed along the line connecting the spring-damper endpoints, often called the line of sight. A positive action force tends to push the action body away from the reaction body. A negative action force tends to pull the action body toward the reaction body.

You can specify the damping and stiffness values as coefficients or use splines to define the relationships of damping to velocity or stiffness to displacement. You can also set the stiffness value to 0 to create a pure damper or set the damping value to 0 to create a pure spring.

You can also set a reference length for the spring, as well as a preload force. By default, Adams View uses the length of the spring damper when you create it as its reference length.

You add a Translational spring damper to your model by defining the locations on two parts between which the spring damper acts. You define the action force that is applied to the first location, and Adams Solver automatically applies the equal and opposite reaction force to the second location.

Learn about Equations Defining the Force of Spring Dampers.

For a Translational spring damper, you can modify:

Learn about Equations Defining the Force of Spring Dampers.

The magnitude of the translational force of a spring damper is linearly dependent upon the relative displacement and velocity of the two locations that define the endpoints of the spring damper. The following linear relation describes the action force: 

force = -C(dr/dt) - K(r - LENGTH) + PRELOAD

where:

A torsion spring force is a rotational spring-damper applied between two parts. It applies the action torque to the first part you select, called the action body, and applies an equal and opposite reaction torque to the second part you select, called the reaction body.

Adams View creates a marker at each location. The marker on the first location you specify is called the I marker. The marker on the second location that you specify is called the J marker. The right-hand rule defines a positive torque. Adams View assumes that the z-axes of the I and J markers remain aligned at all times.

The following linear constitutive equation describes the torque applied at the first body:

torque = -CT*da/dt - KT*(a-ANGLE) + TORQUE

Adams Solver automatically computes the terms da/dt and a. The term a is the angle between the x axes of the I and the J markers. Adams Solver takes into account the total number of complete turns.

You can specify the damping and stiffness values as coefficients or use a spline to define the relationship of damping to velocity or stiffness to displacement. You can also set the stiffness value to 0 to create a pure damper or set the damping values to 0 to create a pure spring. Learn about defining Splines.

You can also set the rotation angle of the torsion spring when it is in its preload state and any preload forces on the spring. By default, Adams View uses the rotation angle of the torsion spring when you create it as its preload angle.

After you’ve created a Torsion spring, you can modify:

A beam creates a translational and rotational force between two locations that define the endpoints of the beam in accordance with either linear or the non-linear theory. It creates markers at each endpoint. The marker on the action body, the first part you select, is the I marker. The marker on the reaction body, the second part you select, is the J marker. . The forces the beam produces are linearly or non-linearly dependent on the relative displacements and velocities of the markers at the beam's endpoints based on the formulation selected. Three formulations are supported to construct the force and torque expressions for this element. By default, the linear beam theory is used which is the one used in the previous versions of Adams. However, other options like full nonlinear Euler-Bernoulli theory or a simplified nonlinear theory can be specified from the Formulation drop down menu.

See Beam example of two markers (I and J) that define the endpoints of the beam and indicates the twelve forces (s1 to s12) it produces.

The x-axis of the J marker defines the centroidal axis of the beam. The y-axis and z-axis of the J marker are the principal axes of the cross section. They are perpendicular to the x-axis and to each other. When the beam is in an undeflected position, the I marker has the same angular orientation as the J marker, and the I marker lies on the x-axis of the J marker. Adams View applies the following forces in response to the translational and the rotational deflections of the I marker with respect to the J marker:

You can use a field element instead of a beam to define a beam with characteristics unlike those that the beam assumes. For example, a field element can define a beam with a nonuniform cross section or a beam with nonlinear material characteristics.

When the Formulation was specified as linear, the following constitutive equations define how Adams Solver uses the data for a linear field to apply a force and a torque to the I marker on the action body of a Beam. The force and torque it applies depends on the displacement and velocity of the I marker relative to the J marker on the reaction body. The constitutive equations are analogous to those in the finite element method.

where:

Adams Solver defines each Kij in the following way:

where:

Adams Solver applies an equilibrating force and torque at the J marker on the reaction body, as defined by the following equations:

L is the instantaneous displacement vector from the J marker to the I marker. While the force at the J marker is equal and opposite to the force at the I marker, the torque is usually not equal and opposite, because of the force transfer.

When using the Formulation = nonlinear option, then the Euler-Bernoulli formulation is used to define the forces and moments. In this case, Adams uses the following constitutive equations to apply a force and a torque to the I marker.

Where {F0} corresponds to the constitutive equations shown above, and N is the axial force on the beam computed as:

N = K11(x - L) + d

The axial force N corresponds to the term Fx computed using linear theory (refer Using the Formulation = linear option). If there is damping (Damping Ratio or Matrix of Damping Terms are defined), the term d corresponds to viscous damping and can be computed as shown above.

The linear theory is the default model for the BEAM statement. The nonlinear theory should be used when the BEAM elements in the model are subject to high axial forces. In those cases, the additional terms in the force/torque equations help stabilize the numerical solution.

When using the option Formulation = string, then a simplified Euler-Bernoulli formulation is used to define the forces and moments. In this case, Adams Solver uses the following constitutive equations to apply a force and a torque to the I marker.

Where {F0} and N are computed as described in Using the Formulation = nonlinear option above. This simplification may provide accurate results faster. Notice the stiffness matrices shown in all of the above equations show only a subset of a complete stiffness matrix. The rest of the entries may be found by applying equilibrium conditions.

After you’ve created a Beam, you can modify the following:

Learn about Constitutive Equations for Beams.

A field element applies a translational and rotational action-reaction force between two locations. Adams View creates markers at each location. The marker on the first location you specify is called the I marker. The marker on the second location you specify is called the J marker. Adams View applies the component translational and rotational forces for a field to the I marker and imposes reaction forces on the J marker.

The field element can apply either a linear or nonlinear force, depending on the values you specify after you create the field.

The following constitutive equations define how Adams Solver uses the data for a linear field to apply a force and a torque to the I marker depending on the displacement and velocity of the I marker relative to the J marker.

For a nonlinear field, the following constitutive equations are defined in the FIESUB subroutine:

Adams Solver applies the defined forces and torques at the I marker. In the linear and nonlinear equations:

Adams Solver computes all variables and time derivatives in the J marker coordinate system.

Adams Solver applies an equilibrating force and torque at the J marker, as defined by the following equations:

Fj = - Fi

Tj = - Ti - L Fi

L is the instantaneous displacement vector from the J marker to the I marker. While the force at the J marker is equal and opposite to the force at the I marker, the torque is usually not equal and opposite, because of the force transfer.

The elements of the stiffness and damping matrices for a field element have mixed units because each of the 6x6 matrices is assembled from four 3x3 matrices, each having consistent units within itself, but different from each other.

The stiffness matrix is multiplied by displacements (both linear and angular) to give the forces (both linear and torsional). Here (x, y, z) is the displacement vector and (a, b, c) are the displacement angles. F and T are the force and torque vectors.

When you create a Field element, you define the location of the force element. SD Suspension creates I and J markers defining the location and direction of the field. To define other properties of the field element, such as its damping values, you must modify the field.

After creating a Field element, you can modify it to define a linear or nonlinear force.