1 / 8

2. Matlab Applications

2. Matlab Applications . a) Parameter estimation (curve fitting)*. Different ways to estimate parameters excel “solver” A graphical user interface (curve fitting toolbox) Matlab command (nlinfit or fmincon) Example

aadi
Download Presentation

2. Matlab Applications

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 2. Matlab Applications a) Parameter estimation (curve fitting)* • Different ways to estimate parameters • excel “solver” • A graphical user interface (curve fitting toolbox) • Matlab command (nlinfit or fmincon) • Example • Creep compliance of a wheat protein film (determination of retardation time and free dashpot viscosity in the Jefferys model) Note: creep is the tendency of a solid material to slowly move or deform permanently under the influence of stresses. Where J is the strain, J1 is the retarded compliance (Pa-1); λret=µ1/G1 is retardation time (s); µ0 is the free dashpot viscosity (Pa s); t is the time.

  2. 2. Matlab Applications Parameter estimation - Creep compliance Experimental Data Note: Unlike brittle fracture, creep deformation does not occur suddenly upon the application of stress. Instead, strain accumulates as a result of long-term stress. Creep is a "time-dependent" deformation. Chewing gum

  3. Method 1) Using Excel Solver

  4. Method 2) CFTtoolbox Parameter estimation - Creep compliance • Use the command of >>cftool

  5. 3. Simulink Simulink Type “simulink” in the command window The graphic interfaces Matlab

  6. Tutorial example x = sin (t) simout

  7. Simulink example 2 Creep compliance of a wheat protein film Using formaldehyde cross-linker • Creep compliance of a wheat protein film (determination of retardation time and free dashpot viscosity in the Jefferys model) Where J is the strain, J1 is the retarded compliance (Pa-1); λret=µ1/G1 is retardation time (s); µ0 is the free dashpot viscosity (Pa s); t is the time. • The recovery of the compliance is following the equation (t >t1): Where t1 is the time the stress was released. Solve using Simulink model Parameters: J1 = a = 0.38 Mpa-1; λret = b = 510.6 s; µ0 = c = 260800 Mpa s; t1=5000

  8. 4. Simulink examples Creep compliance of a wheat protein film Simulation result

More Related