Dr. Bijan Mohammadi
The SIGMA aircraft design company is a knowledge-based company with more than 10 years expriences as an unique private aircraft design beuraue, in Iran. SIGMA have excelent expriences on the entire aircraft design from blank sheet to prototyping and flight tests. Furthermore, design and advanced analysis of arial structure and mechanical systems of aircraft are our skill and strength points. It has been performed, more than 25 conventional, national, demonstrative and innovative projects by our team.


FLAi is a comprehensive graphical developed software by cooperation of SIGMA fatigue life team with Amirkabir University of Technology (AUT). The purpose of FLAi software design is to calculate the component’s life of the structures under fatigue spectrum loading with focus on aircraft structures. Three independent environments are included in this software as below.

Software environments:

    •Life estimation of crack-free components by semi-analytical method
    •Life estimation of cracked panels by semi-analytical method
    •Life estimation of thin panels by FE method


Software capability

    Semi-Analytical Package:
        •Fatigue life based on S-N curve analysis
        •Fatigue life and fatigue crack growth investigation
        •Cycle counting for complex load spectrum
        •Covering over 600 types of materials
        •Geometry database for Stress intensity factor
        •Fatigue life estimation of repaired panel
        •Fatigue life estimation of stiffened panel


    FEM package
        •Crack-tip trajectory estimation
        •Automatic crack propagation
        •Multi-crack definition
        •Edge-crack definition
        •Macro Programming Editor


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