Cantilever Beam Design for Projectile Internal Moving Mass Systems

2010 ◽  
Author(s):  
Jonathan Rogers ◽  
Mark Costello
Keyword(s):  
Cantilever Beam ◽  
Moving Mass ◽  
Beam Design

Cantilever Beam Design for Projectile Internal Moving Mass Systems

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Jonathan Rogers ◽  
Mark Costello
Keyword(s):  
Cantilever Beam ◽  
Damping Ratio ◽  
Effective Control ◽  
Moving Mass ◽  
Control Mechanisms ◽  
Control Force ◽  
Internal Mass ◽  
Mass System ◽  
Electromagnetic Actuators ◽  
Beam Design

Internal masses that undergo controlled translation within a projectile have been shown to be effective control mechanisms for smart weapons. However, internal mass oscillation must occur at the projectile roll frequency to generate sufficient control force. This can lead to high power requirements and place a heavy burden on designers attempting to allocate volume within the projectile for internal mass actuators and power supplies. The work reported here outlines a conceptual design for an internal translating mass system using a cantilever beam and electromagnetic actuators. The cantilever beam acts as the moving mass, vibrating at the projectile roll frequency to generate control force. First, a dynamic model is developed to describe the system. Then the natural frequency, damping ratio, and length of the beam are varied to study their affects on force required and total battery size. Trade studies also examine the effect on force required and total battery size of a roll-rate feedback system that actively changes beam elastic properties. Results show that, with proper sizing and specifications, the cantilever beam control mechanism requires relatively small batteries and low actuator control forces with minimum actuator complexity and space requirements.

scholarly journals Miniature on-fiber extrinsic Fabry-Perot interferometric vibration sensors based on micro-cantilever beam

2019 ◽  
Vol 8 (1) ◽  
pp. 293-298 ◽  
Author(s):  
Weiyi Ma ◽  
Yi Jiang ◽  
Han Zhang ◽  
Liuchao Zhang ◽  
Jie Hu ◽  
...  
Keyword(s):  
Cantilever Beam ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Vibration Sensor ◽  
Fiber Axis ◽  
Vibration Sensors ◽  
Beam Design ◽  
Cantilever Length ◽  
Fabry Perot ◽  
Micro Cantilever

Abstract An on-fiber extrinsic Fabry–Perot interferometric (EFPI) vibration sensor based on micro-cantilever beam is proposed and experimentally demonstrated. The micro-cantilever beam, with a cantilever length of 80μm and a cantilever thickness of 5μm, is created perpendicular to the fiber axis by using the femtosecond laser micro-machining technique. The on-fiber vibration sensor has same diameter with that of the single mode fiber. An acceleration sensitivity of 11.1 mV/g@300 Hz in the range of 0.5-5g is demonstrated experimentally. This on-fiber and micro-cantilever beam design allows for the sensor to be smaller size and higher temperature resistance.

Dynamics of Joints with Clearance for a Cantilever Beam Subjected to a Moving Mass

2012 ◽  
Vol 229-231 ◽  
pp. 652-655
Author(s):  
Guo Lai Yang ◽  
Wei Dong
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Cantilever Beam ◽  
Experimental Test ◽  
Work Conditions ◽  
Moving Mass ◽  
Test Bed ◽  
Euler Beam ◽  
Mode Method ◽  
Numeric Calculation

This paper presents theoretical analysis, numeric calculation and experimental test for a cantilever beam subjected to a moving mass with clearance. Coupled transverse vibration equations of cantilever beam subjected to a moving rigid body with clearance were formulated by discretizing Euler beam based on assumption mode method. Numeric computation code was developed. A test bed for measuring joint clearance was constructed. Dynamic clearance tests were carried out under different work conditions. The accuracy of theoretical analysis was verified by comparison between experimental data and simulated results.

Modeling and Dynamic Analysis of Cantilever Beam Coupled with Moving Mass

2011 ◽  
Vol 105-107 ◽  
pp. 250-253
Author(s):  
Xing Wei Zhao ◽  
Zhen Dong Hu
Keyword(s):  
Cantilever Beam ◽  
Numerical Solutions ◽  
Multibody System ◽  
Variable Coefficients ◽  
Dynamic Responses ◽  
Moving Mass ◽  
Time Varying ◽  
System A ◽  
Varying Mass ◽  
Made In

A system of cantilever beam coupled with moving mass is investigated in this paper. Based on the time varying feature of multibody system, a dynamic model of the mass moving along the cantilever beam is established. The time varying motion equation including time varying mass and stiffness is derived by using the generalized Hamiltion’s principle, which results to a partial differential equation with variable coefficients. The nonlinearity of the equation is featured by those variable coefficients. To deal with the nonlinearity, methods of assumed modal shapes, Runge-Kutta are occupied. Then, a time varying system of a cantilever beam with stepwise sections coupled with a moving mass is given as an example. Numerical solutions of the dynamic responses of the system are achieved and certain analyses are made in the form of graphs.

Atlas table: a dynamic innovative support device for the coming obesity epidemic

2017 ◽  
Vol 4 (1) ◽  
pp. 9-14
Author(s):  
Anna Smart ◽  
Zachary L Bercu ◽  
Haris Shekhani ◽  
Janice Newsome ◽  
Jonathan G Martin
Keyword(s):  
Cantilever Beam ◽  
Mobility Limitations ◽  
Chest Compressions ◽  
Design Features ◽  
Obesity Epidemic ◽  
Additional Weight ◽  
Beam Design ◽  
Medical Need ◽  
Support Device ◽  
Overlay Design

With obesity rates increasing rapidly, the Atlas table, a modular table overlay, was developed to address the unmet medical need of the inability of current interventional tables to support patients weighing more than 450 lbs. Current procedural tables have a posted weight limit of 500 lbs. In practice, this limit is 450 lbs due to the permanent installation of a 50 lb dye injector at the foot of the table. Instability is reported in patients in the range of 250–450 lbs, resulting in the need to modify how the table is placed over the base. Additional weight and mobility limitations exist due to the cantilever beam design of the existing table that allows movement of the C-arm fluoroscope to move around the entire table. A clinical device should bear all of the weight of an 800 lb patient, without failing during emergency chest compressions, which makes the weight capacity necessary 1200 lbs. This must be accomplished without obstructing the movement of the C-arm of the existing table or requiring a more than 2% increase in radiation. Our table overlay design features a lightweight, radiolucent tabletop and four modular height-adjusting legs that move with the existing table and do not require separate controls. The legs clamp to the radiolucent tabletop securely but not permanently so that they can be moved when needed, with buttons that swing out and cause the table to raise or lower by being trigger by contact from the existing table. The proposed design safely holds and lifts 1200 lbs.

Study on Design Method of Non-Uniform Beam of Mechanical Structure

2012 ◽  
Vol 479-481 ◽  
pp. 2568-2571
Author(s):  
Guo Zhi Zhang
Keyword(s):  
Cantilever Beam ◽  
Design Method ◽  
New Method ◽  
Mechanical Structure ◽  
Uniform Beam ◽  
Beam Design ◽  
Mechanical Models ◽  
Typical Parameter

The non-uniform equivalent beam design method for non-uniform beam of mechanical structure was proposed. Its equivalent mechanical models of tension or compression and bending was established. Moreover, the erro between the result of FEM and the result of non-uniform equivalent beam design method is less than 5% so as to verify the accuracy of non-uniform equivalent beam design method for typical parameter bending cantilever beam and the tension link. The study in the paper provides a new method and basis for design and calculation of similar mechanical structures.

Dynamic Deflection of a Cantilever Beam Carrying Moving Mass

2014 ◽  
Vol 592-594 ◽  
pp. 1040-1044
Author(s):  
Shakti P. Jena ◽  
D.R. Parhi
Keyword(s):  
Differential Equation ◽  
Numerical Analysis ◽  
Boundary Conditions ◽  
Cantilever Beam ◽  
Continuum Mechanics ◽  
Fourth Order ◽  
Moving Mass ◽  
Kutta Method ◽  
Beam Structure ◽  
Runge Kutta Method

In the present work, the dynamic deflection of a cantilever beam subjected to moving mass has been investigated theoretically and numerically. The mass is moved by an external force. The effects of mass magnitude and the speed of the moving mass on the response of the beam structure have been investigated. Using continuum mechanics the differential equation for the systems have been developed and solved by fourth order Runge-Kutta method with different boundary conditions. Numerical analysis has been carried out with different examples to describe the response of the beam structure.

Dynamic Response Analysis of Cantilever Beam under Moving Mass by Time-Discontinuous Galerkin Finite Element Method

2011 ◽  
Vol 130-134 ◽  
pp. 1234-1238
Author(s):  
Jian Wei Hao ◽  
Jian Li Ge
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Response ◽  
Discontinuous Galerkin ◽  
Cantilever Beam ◽  
Numerical Dissipation ◽  
Response Analysis ◽  
Moving Mass ◽  
Moving Force ◽  
Element Method

A time-discontinuous Galerkin (TDG) finite element method for analyzing the dynamic response of cantilever beam subjected to moving force or moving mass is presented. The cantilever beam is discretized in space by finite element method, and the time-varying dynamic equations are derived. The TDG finite element method by which both the displacements and velocities are approximated as piecewise linear functions in time domain and discontinuous at the discrete time levels is adopted to solve the differential equations. This method inherits third order accuracy and the unconditionally stable behavior, moreover, it is endowed with large stability limits and controllable numerical dissipation. The numerical solutions are accord with analytic ones, which validates the feasibility and superiority of this method for solving the dynamic response of cantilever beam under moving force or moving mass.

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