VM-EXD-MECH-007

VM-EXD-MECH-007
Simple Pendulum with Simple Harmonic Motion (SHM)

Overview

Reference: Any Basic Kinematics Book
Analysis Type(s):

Explicit Dynamics 3-D (Fully Rigid)

Elements: Rigid Body Elements
Boundary Conditions: Fixed Constraint, Joint Load
Structural Interactions:No
Fluid-Structure Interactions:No
Connections:Revolute Joint
Materials:Steel

Test Case

A simple pendulum has a simple harmonic motion (SHM) about its hinged point:

Figure 244: Pendulum Schematic

Pendulum Schematic

The SHM is given by θ = 1.571*sin (0.5235*t) rad. The hinge point coordinates are (0, 0, -35.56) mm.

The analysis finds the relative angular acceleration of pendulum after t = 3s.

Material PropertiesGeometric PropertiesLoading

E = 2000000 MPa

ν = 0.3

Hinge point = (0, 0, -35.56) mmRotation θ = 1.571*sin (0.5235*t) rad

Analysis

The pendulum undergoes SHM in the X-Z plane about the hinge.

The angular acceleration of pendulum is given by:

Results Comparison

ResultsTargetExplicit Dynamics [1]Error (%)
Relative angular acceleration of pendulum after t = 3.0031 s (rad/s2)-0.433-0.433920.212
  1. To compare this result to that obtained using rigid body dynamics, see VM-WB-MECH-053.