5. Acceleration Analysis: F-14 Wing Sweep
The following acceleration analysis is based on the input shown in Section 2, position analysis shown in Section 3, and velocity analysis shown in Section 4. The linear actuation acceleration was numerically derived using a forward difference algorithm in order to allow analysis of any input motion curve without needing to re-derive equations . The resulting linear actuation acceleration curve is shown below.
Linear Actuation Acceleration vs Time
The equations used to calculate rotational accelerations of the input (actuator) and output (wing) links were derived from the 3-bar velocity loop closure equation. Again, This results is a two-by-two system of linear equations which was solved over the full input domain. Similar to the rotational velocity, the magnitude of the actuator link rotational acceleration suggests that this is negligible for purposes of analysis. The same is true for the wing link rotational acceleration. This contributes to the stability and control in during operation of the mechanism. Plots of these rotational accelerations versus actuator link length and time are shown below.
Input (Actuator) Link Rotational Acceleration vs Actuator Length and vs Time
Output (Wing) Link Rotational Acceleration vs Actuator Length and vs Time
The linear accelerations of point A and the COM of the wing can be calculated directly from the rotation velocity and acceleration of the wing link. Because the distances from the ground pin to these points does not change, the acceleration at each point only has two components: rotational and centripetal. Similar to the linear velocity analysis, the linear acceleration of the COM is approximately three times that of point A.
Point A Linear Acceleration vs Actuator Length and vs Time
Wing COM Linear Acceleration vs Actuator Length and vs Time