2 dof spring mass system matlab tutorial pdf

The simulink model uses signal connections, which define how data flows from one block to another. If you complete the whole of this tutorial, you will be able to use matlab to integrate equations of motion. Im trying to integrate the mathematical model of a landing gear drop test, modeled as a two dof mass spring damper system. Derive equations of motion for the system using x 1 and x 2 as independent coordinates y 1 and y 2 as independent coordinates chp3 11. Evaluation of methods for analysis of multidegreeoffreedom. Mar 12, 2015 i have a system consisting of two bodies it and ic connected by a rotational spring constant k. The theory the unforced massspring system the diagram shows a mass, m, suspended from a spring of natural length l and modulus of elasticity if the elastic limit of the spring. Numerical analysis and design of a dynamic system with.

Lect02 2dof spring mass systems compatibility mode free download as pdf file. But then the coupling on the right side would constrain how far the right mass would tilt, which could keep the system together if the proportions were correct. For the free vibration of a singledegreeoffreedom system with mass m, spring constant k,and viscous damping c, the system undergoes a dynamic displacement xt measured from the static equilibrium position of the mass. Ansys tutorials for undergraduate mechanical engineering courses. Simulink tutorial introduction this document is designed to act as a tutorial for an individual who has had no prior experience with simulink. Spring mass system linear spring frictionless table m x k lagrangian l t v l t v 1122 22. Another problem faced when solving the mass spring system is that a every time different type of problem wants to be solved forced, unforced. This is shown in the block annotations for spring1 and spring2. Learn more about simulink matlab and simulink student suite. Position evolution over time of two masses which are released from their initial positions until they reach steady state regime due to damping. Oct 02, 2015 two mass damper spring system in simulink. A two degrees of freedom system consisting of two masses connected by springs and subject to 3 di.

The direct approach of general dynamic optimal control. The first natural mode of oscillation occurs at a frequency of. Simulink tutorial introduction starting the program. Feb 18, 2016 design spring mass damping system in simulink part 1 duration. They are not intended to be used as guides for determining suitable modeling methods for any application. Computer simulation of massspring system with damping 2 dof. Dec 09, 2011 position evolution over time of two masses which are released from their initial positions until they reach steady state regime due to damping. The example in this section is about ideal case of single spring and single mass system and it is assumed that there is no friction, no damping i. This example shows two models of a double mass spring damper, one using simulink inputoutput blocks and one using simscape physical networks. Thus the motions of the mass 1 and mass 2 are out of phase.

State space model of multiple dof springmassdamper. Jan 09, 2014 this video is from the springmass matlab tutorial at. Consider a spring mass system shown in the figure below. Assumed sign conventions the stiffness displacement method 2. Modelling of a springmassdamper in simulink, 1722016. Springmassdamper system case study video matlab toggle main navigation. Evaluation of methods for analysis of multidegreeof. A sensor samples the displacement of the mass at f s 1 hz. Two mass damper spring system in simulink matlab answers. A damper impedes the motion of the mass by exerting on it a force proportional to speed, with damping constant b 0. Inputoutput connections require rederiving and reimplementing the equations.

Spring mass system displacement matlab answers matlab. In this example, you have learned how to model the motion of a mass tied to a vertical spring. Chulachomklao royal military academy nakhonnayok, thailand. Gossard goes over obtaining the equations of motion of a 2 dof system, finding natural frequencies by the characteristic equation, finding mode shapes.

In reality, you cannot have this kind of idea system. Modeling and analysis of dynamic mechanical systems lar 07. You can represent each mass as a series combination of an. Modeling and analysis of dynamic mechanical systems.

Simulink is an extra toolbox that runs on top of matlab. Using simulink to analyze 2 degrees of freedom system. Springmassdamper system case study discover how matlab supports a. The number of dof is a characteristic of the system and does not depend on the particular set of coordinates used to describe the configuration. When you see this kind of springmass system, each mass is the building. Statespace model of a mechanical system in matlabsimulink. Springmass system euler integration simcafe dashboard.

We next specify the initial conditions and run the code that we have so far as shown in the video below. Dec 03, 20 build a 2 dof spring mass damper in simulink more to come. Matlab is a high performance language for technical computing. This model is for an active suspension system where an actuator is included that is able to generate the control force u to control the motion of the bus body. Some of the typical uses of matlab are given below. Discover how matlab supports a computational thinking approach using the classic springmassdamper system. Simulations of linear time independent lti systems are easily accomplished in matlab using builtin functions for.

The mass m 2, linear spring of undeformed length l 0 and spring constant k, and the linear dashpot of dashpot constant c of the internal subsystem are also shown. In this section, we introduce the statespace and transfer function representations of dynamic systems. Dynamics and vibrations matlab tutorial brown university. Jan 19, 2018 you can go through the videos either before or after completing this tutorial. Two mass spring system pid control matlab answers matlab. Select element typeconsider the linear spring shown below.

You can represent each mass as a series combination of an integrator and a gain. Design spring mass damping system in simulink part 1 duration. Learn more about 2dof, mass, spring, ode, differential equations, system of differential equations, second, order, differential, equation, two, degrees, of, freedom. You can go through the videos either before or after completing this tutorial. Spring mass damper 2 degree freedom the direct approach of general dynamic optimal control. Gui matlab code to display damped, undamped, forced and unforced mass spring systems melanie garcia. A nonlinear system has more complicated equations of motion, but these can always be arranged into the standard matrix form by assuming that the displacement of the system is small, and linearizing. Learn more about mass spring damper, two degrees of freedom.

Solving second order ordinary differential equation using simulink. A massspringdamper system and a damped pendulum under free vibration were modeled using the familiar application of newtons second law of motion, eq. Simulink modeling of a springmassdamper system this video describes the use of simulink to simulate the dynamic equations of a page 829. Finally, the damper is just a gain without an integrator, with the value of the gain. A method for obtaining the stiffness matrix and load vector from ansys. How do we interpret what matlab gives us with this command in the first order form of the state variable model. Euler integration we start by specifying constants such as the spring mass m and spring constant k as shown in the following video. Consider a springmass system shown in the figure below. Run the command by entering it in the matlab command window. Ansys tutorials for undergraduate mechanical engineering. Build a 2 dof spring mass damper in simulink more to come. Two dof non linear mass spring damper system with lookup. A vertical mass spring system in simple harmonic motion.

Pdf statespace model of a mechanical system in matlabsimulink. You clicked a link that corresponds to this matlab command. Chapter 2 introduction to the stiffness displacement method. Dynamics and vibrations matlab tutorial school of engineering brown university this tutorial is intended to provide a crashcourse on using a small subset of the features of matlab.

The system and the two free body diagram are the following. Learn more about spring mass, displacement, ode45 matlab. The equations of motion for the 2 dof system are derived. Likewise, you can model each spring the same way, except the value of the gain will be either k or 1k depending on your choice of input and output. For a system with n degrees of freedom, they are nxn matrices the spring mass system is linear. The spring is of length l and is subjected to a nodal tensile force, t directed along the xaxis. Pdf statespace model of a mechanical system in matlab. Double massspringdamper in simulink and simscape matlab. System parameters m1 14 bus body mass 2500 kg m2 suspension mass 320 kg k1 spring constant of suspension system 80,000 nm k2 spring constant of wheel and tire 500,000 nm b1 damping constant of suspension system 350 n. Another common misconception is that the model shown in figure 1. State space model of multiple dof springmassdamper system. In the above, is to be taken as each of the following 1. Introduction in order to analyze a complex dynamic mechanical system it is essential to first understand the properties of the simplest possible dynamic mechanical system. Bookmark file pdf dynamics and vibrations matlab tutorial brown universitysystem in this video we take a look at a twocart springmassdamper system.

To learn more about a certain function, you should use the online help. Applying newtons law, the equation of motion of the system is represented by m c k f x figure 2. Solving problems in dynamics and vibrations using matlab. When the suspension system is designed, a 14 model one of the four wheels is used to simplify the problem to a 1d multiple spring damper system. It is assumed that the reader has already read through the beginner and intermediate matlab tutorials. Frequencyresponse functions for modal analysis matlab modalfrf. The value of the gain will be either m or 1m depending on how you set things up. How to model a simple springmassdamper dynamic system in matlab.

Application on general software tawiwat veeraklaew, ph. At this requency, both masses move together, with the same amplitude and in the same direction so that the coupling spring between them is neither stretched or compressed. Gui matlab code to display damped, undamped, forced and. Chapter 2 introduction to the stiffness displacement. In this tutorial an approach will be outlined to obtain socalledprototype models of the mechanical part of a mechatronic system. Modeling a system with two degrees of freedom matlab. This is shown in the block annotations for the spring and one of the integrator blocks. Physical connections make it possible to add further stages to the mass spring damper simply by using copy and paste. These exercises are intended only as an educational tool to assist those who wish to learn how to use ansys.

These models may be derived either from physical laws or experimental data. Lets use simulink to simulate the response of the massspringdamper system described in intermediate matlab tutorial document. Nodes 2 and 3 have uy and uz dof constrained to zero displacement. Solving problems in dynamics and vibrations using matlab parasuram harihara and. Using the standard response for a unit impulse which for a single degree of freedom system is, then we write as hence, the general solution becomes. A onedimensional discretetime oscillating system consists of a unit mass, m, attached to a wall by a spring with elastic constant k 1. Derive equations of motion for the system using x 1 and x 2 as independent coordinates. Applying f ma in the xdirection, we get the following differential equation for the location xt of the center. The first step in the control design process is to develop appropriate mathematical models of the system to be controlled. Math and computation algorithm development modeling, simulation and prototyping mfiles files that contain code in matlab language are called mfiles. Select a displacement functiona displacement function ux is assumed. This video is from the springmass matlab tutorial at. Mass spring system equation help matlab answers matlab.

Handson learning with computer simulation modules for. For a system with two masses or more generally, two degrees of freedom, m and k are 2x2 matrices. The state vector consists of the angles and angular rates of the bodies wrt an inertial frame. Where are 2 by 1 vectors and and are the mass and sti. From this very simple example, you can extend to more and more complicated situation which is closer to real engineering example.