Post by crotinat on Nov 15, 2007 13:57:19 GMT -5
The position proposed deals with a Numerical tool for the optimal design of mechanical structures and mechatronics systems
Compliant joints and structures are very interesting when high precision systems are required, because they don’t present friction and backlash. More generally, a compliant structure must be flexible enough to elastically deform, and stiff enough to transmit mechanical forces. The compromise between these two aspects depends mainly on the application viewed.
CEA LIST has developed a numerical tool for helping planar compliant structures design, like truss structures, using a stochastic optimization method, i.e. evolutionary algorithm. This tool, developed with MatLab language, allows to automatically design mechatronics systems made of compliant mechanisms. Thus, considering a given schedule of conditions, the software proposes optimal designs of structures, for one or many mechanical (or control-based) criteria defined by the user. Optimization variables are for example : shape, dimensions, material (classical and/or piezoelectric), actuators location, etc. To do so, the performance criteria available (displacements, forces, etc.) are calculated using a finite element model of the structure, which has be especially developed and implemented in the software.
The post-doctoral research work, proposed here, has got many goals :
- To update and integrate the few existing versions of the software (which were developed simultaneously and without links, for different limited case studies)
- To study, using well chosen benchmark cases, the present software limitations (case study incompatibilities: multi-actuation, multi-dof, boundary conditions, etc.), that play again versatility and easy use of the optimization method
- To ensure programming corrections to allow a good functioning of the software, and to enlarge its use possibilities
- To propose a set of tests and benchmark cases to rapidly validate each programming modification done, and each new development of the software
- To make the present software evolve, by improving the existing mechanical criteria (Von Mises stress, buckling critical load), and eventually by adding new optimization criteria
- To modify the software to reach better convergence speed, and/or to allow three-dimensional model implementation
- To write a user manual of the software
- To develop annex functions for the data exportation, to allow post-calculation or treatment using commercial finite element and CAD softwares
- To develop the function ergonomics for the visualization of the results (deformed shape drawing, etc.)
The results will help to dispose of an efficient numerical tool for the optimal preliminary design of mechanical and mechatronics systems. The post-doctoral fellow will also be involved, thanks to the programming works he will be in charge, to participate to the many collaborative projects of the Laboratory. These projects have the aim to develop compliant robotic and micro robotic systems prototypes, proposed by the optimal design numerical tool, for real applications in the health field.
Adminitrative details :
Location : CEA LIST, Fontenay-aux-Roses (Paris), FRANCE
Period : 2 years (1 year renewable 1 time)
Equipment : Calculation and simulation softwares
Applicant specialization : PhD in mechanics or applied mathematics
Experience in programming (MatLab), modelisation, structural mechanics, and finite elements method
CV, publication list and applying letter must be sent to :
Christine ROTINAT-LIBERSA, Ing. PhD. (christine.rotinat-libersa@cea.fr)
CEA LIST, DTSI SRI LRM, Bât. 38.1
18 route du Panorama, BP6
92265 Fontenay aux Roses cedex
FRANCE
Compliant joints and structures are very interesting when high precision systems are required, because they don’t present friction and backlash. More generally, a compliant structure must be flexible enough to elastically deform, and stiff enough to transmit mechanical forces. The compromise between these two aspects depends mainly on the application viewed.
CEA LIST has developed a numerical tool for helping planar compliant structures design, like truss structures, using a stochastic optimization method, i.e. evolutionary algorithm. This tool, developed with MatLab language, allows to automatically design mechatronics systems made of compliant mechanisms. Thus, considering a given schedule of conditions, the software proposes optimal designs of structures, for one or many mechanical (or control-based) criteria defined by the user. Optimization variables are for example : shape, dimensions, material (classical and/or piezoelectric), actuators location, etc. To do so, the performance criteria available (displacements, forces, etc.) are calculated using a finite element model of the structure, which has be especially developed and implemented in the software.
The post-doctoral research work, proposed here, has got many goals :
- To update and integrate the few existing versions of the software (which were developed simultaneously and without links, for different limited case studies)
- To study, using well chosen benchmark cases, the present software limitations (case study incompatibilities: multi-actuation, multi-dof, boundary conditions, etc.), that play again versatility and easy use of the optimization method
- To ensure programming corrections to allow a good functioning of the software, and to enlarge its use possibilities
- To propose a set of tests and benchmark cases to rapidly validate each programming modification done, and each new development of the software
- To make the present software evolve, by improving the existing mechanical criteria (Von Mises stress, buckling critical load), and eventually by adding new optimization criteria
- To modify the software to reach better convergence speed, and/or to allow three-dimensional model implementation
- To write a user manual of the software
- To develop annex functions for the data exportation, to allow post-calculation or treatment using commercial finite element and CAD softwares
- To develop the function ergonomics for the visualization of the results (deformed shape drawing, etc.)
The results will help to dispose of an efficient numerical tool for the optimal preliminary design of mechanical and mechatronics systems. The post-doctoral fellow will also be involved, thanks to the programming works he will be in charge, to participate to the many collaborative projects of the Laboratory. These projects have the aim to develop compliant robotic and micro robotic systems prototypes, proposed by the optimal design numerical tool, for real applications in the health field.
Adminitrative details :
Location : CEA LIST, Fontenay-aux-Roses (Paris), FRANCE
Period : 2 years (1 year renewable 1 time)
Equipment : Calculation and simulation softwares
Applicant specialization : PhD in mechanics or applied mathematics
Experience in programming (MatLab), modelisation, structural mechanics, and finite elements method
CV, publication list and applying letter must be sent to :
Christine ROTINAT-LIBERSA, Ing. PhD. (christine.rotinat-libersa@cea.fr)
CEA LIST, DTSI SRI LRM, Bât. 38.1
18 route du Panorama, BP6
92265 Fontenay aux Roses cedex
FRANCE