ACCELEROMETER

Description

Figure 1. Connection type ACCELEROMETER.

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

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

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 the computed velocity and acceleration in the local directions at node b. Let $T_{ij}$ be the transformation from ${\mathbf{e}}_i^a$ to ${\mathbf{e}}_i^b$. Then the ACCELEROMETER connection measures velocity and acceleration as

where the derivatives above are time derivatives in a system moving with ${\mathbf{e}}_i^a$.

In two-dimensional and axisymmetric analyses $u_3=0$.

Summary