Optimization value not changing with runs and iterations

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello , 

 

I am trying to match the experimental results of tensile tests conducted on soft tissues with the developed user material in Ls dyna FEA code. I am creating my objective function in four responses. In response 1, i am creating two vectors v_1 and v_2 which defines the experimental time and measured force and in response 2(r_2) is defined by two vectors v_3 and v_4 through a csv file created during the simulation run. In response r_1 and r_2, i am using linear interpolations operations as, for example for one of the tests, linint( v_1, v_2, 0:6.99:0.005), here 6.99 is the total time of the event, 0.005 test frequency and for response r_2 it is linint(v_3, v_4, 0:6.99:0.005), hyperstudy is not able to extract the values and showing me a warning that non-scalar values cannot be used. Response 3 is created as 100*(r_1 - r_2)/max(r_1) and response r_4 as mag(r_3)/sqrt(v_1 or v_2) as both v_1 and v_2 are of same lengths. I am running this using genetic algorithm. Though iterations are running but value of objective functions which is min(r_4) remains the same. Kindly please help me out in resolving this issues out. The pics are attached for references. 

<?xml version="1.0" encoding="UTF-8"?>2.JPG

<?xml version="1.0" encoding="UTF-8"?>1.JPG

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited September 2016

    I would first check if your input files are written correctly. You can do this by comparing them with each other and making sure that the DV values are changing.

    If they are written correctly, next is to check if the simulation is running correctly. Are you pointing directly to the executable or are you running a script? If you are running a script, there may be places that you had to use HyperStudy environment variables.

    Hope these help as a starting point

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