Engineering models of complex mechanical systems can be simplified using the ideas of translational or torsional mass, stiffness, and damping. Vibrations in mechanical systems occur when a system oscillates around an equilibrium position due to an external force or internal dynamics, and can be classified into free or forced vibration. Using concepts of linear algebra, differential equations, and calculus we are able to represent the response of these systems mathematically and graphically.
Analysis: Identify Multi-Degree-of-Freedom Energy Totals
Analysis: Lagrange's Equations and Equations of Motion
Analysis: Steady-State Response, Impedence
Analysis: Frequency Equation, Amplitudes
Analysis: Particular Solution, Base Excitation
MatLab: Given Initial Conditions, Numerically Solve for Free Response
The overarching goal of this project was to design, provide calculated justification for, and fabricate a launching mechanism for a racquetball with a mass of 0.040 kilograms (kg) and diameter of 57 millimeters (mm). The dimensions of this mechanism were constrained to fit within a space of 3 feet x 3 feet x 3 feet. Furthermore, the projectile range had to extend a total of twelve feet from the site of launch.
After construction and testing, teams were invited to compete in a free-for-all setting with buckets placed at several intervals. Within two minutes, each group attempted to launch as many racquetballs into the buckets as possible. Our team placed the second-highest, with a score of twenty-nine successful shots.
Testing and Marking Launch Settings
Testing the Maximum Range of the Launcher
Locking the Linear Launch Angle
Determining Launch Distance
Calculating Projectile Trajectories
The project involves optimizing the launch angle, initial height, and velocity to ensure the ball reaches the specified distances, while assuming negligible drag and friction. The preliminary design centered on a linear launcher using a PVC tube, springs, and a crossbar to control the force and velocity of the ball's launch. Through mathematical analysis and simulations, our team confirmed the viability of the design, with calculated velocities and trajectories aligning with the project’s requirements and expected performance.
Calculating Reasonable Spring Constant and Displacement for a Linear Launcher
The primary focus of this section was calculating and selecting the appropriate spring constant and displacement to achieve the necessary launch velocity, using a spring with a calculated constant of 11.5 N/m. A revised linear launcher design incorporates a PVC tube, extension springs, and a crossbar mechanism to transfer energy from the spring to the ball. Mathematical analysis, including the work-energy theorem, confirms that the spring displacement and velocities fall within achievable ranges, with expected deviations in trajectory due to neglecting drag and friction.
Calculating Angle of Launch and Corresponding Spring Extension for a Rotational Launcher
The project builds on previous work by applying rigid body kinematics to model the system, focusing on the catapult arm's spring displacement and the launch angle required for each target. Using conservation of mechanical energy, the report details calculations for the moment of inertia, center of mass, and the relationship between spring displacement, angle of launch, and initial velocity. The analysis, verified through Excel optimization software, confirms that the chosen spring and angular deflection provide feasible solutions, while trajectory predictions are consistent with expected physical outcomes, though small deviations due to drag and friction are anticipated.
A catalogued material and structural failure of Carowinds' trademark Fury 325 caught public attention in 2023. The nature of the crack was defined post-failure, and occurred at the welding site of a rigid support beam which shifted the constraints in a sliding fashion. While the site intended to constrain a horizontal load as well as gravitational and centrifugal forces from the coaster, the failure resulted in this section of the coaster being unable to withstand such loads, and posed a threat to public safety. Diagnostics of the material/structural fracture was performed through Finite Element Analysis (FEA)– the simulation of physical faults and phenomena with assistance from mesh techniques. Our team chose to write a report on the applications of FEA with respect to material properties touched on in this course.
Static Fatigue Analysis
For FEA, comprehensive data is provided to a simulator which translates data into a mesh. A series of complex calculations are performed on individual elements, and the total result is interpolated with a feasible degree of accuracy. Throughout the course, key material properties like Young's Modulus, Poisson's Ratio, and the Stress-Strain Curve proved essential for understanding how materials respond to external forcing. Young's Modulus measures material stiffness, indicating how much a material deforms under load, while Poisson's Ratio describes the relationship between axial and lateral strain during deformation. The Stress-Strain Curve illustrates how materials behave under tensile stress, showing their elastic limit, yield strength, and ultimate tensile strength. All of these respective points of data along a defined curve are crucial nodes which drive these FEA simulations.