ACCELEROMETER

ProductsAbaqus/Explicit

Description

The ACCELEROMETER connection does not impose kinematic constraints. It defines three local directions at node a and three local directions at node b. The ACCELEROMETER connection's formulation is similar to that for the CARTESIAN connection. The ACCELEROMETER connection measures the position of node b relative to node a

x = e_{1}^{a} \cdot (x_{b} - x_{a}); y = e_{2}^{a} \cdot (x_{b} - x_{a}); and z = e_{3}^{a} \cdot (x_{b} - x_{a}) .

There are no available components of relative motion for the ACCELEROMETER connection. The connector displacement components are

u_{1} = x - x_{0}, u_{2} = y - y_{0}, and u_{3} = z - z_{0},

where $x_{0}$ , $y_{0}$ , and $z_{0}$ are the initial coordinates of node b relative to node a.

The ACCELEROMETER connection measures velocity and acceleration in the local directions at node a as if node a were an inertial frame. In contrast to the CARTESIAN connection, the ACCELEROMETER connection reports all the computed quantities (such as displacement, position, velocity, and acceleration) in the local directions at node b. Let $T_{i j}$ be the transformation from $e_{i}^{a}$ to $e_{i}^{b}$ . Then the ACCELEROMETER connection measures velocity and acceleration as

v_{i} = T_{i j} \frac{d u_{j}}{d t} and a_{i} = T_{i j} \frac{d^{2} u_{j}}{d t^{2}},

where the derivatives above are time derivatives in a system moving with $e_{i}^{a}$ .

In two-dimensional and axisymmetric analyses $u_{3} = 0$ .

Summary


ACCELEROMETER
Basic, assembled, or complex:	Basic
Kinematic constraints:	None
Constraint force output:	None
Available components:	None
Kinetic force output:	None
Orientation at a:	Optional
Orientation at b:	Optional
Connector stops:	None
Constitutive reference lengths:	None
Predefined friction parameters:	None
Contact force for predefined friction:	None