Nonsmooth and Nonconvex Mechanics

The field of nonsmooth and nonconvex mechanics is a newly developed multi-interdisciplinary research area, which involves a powerful combination of theoretical analysis in mathematical modelling of natural systems, finite deformation theory, modern physics, material science, nonlinear partial differential equations,  global optimization,  variational methods, dynamical systems, global optimization, numerical algorithms  and scientific computations. This field has undergone very considerable development in a remarkably short time. 

Nonsmooth mechanics is a research topic that integrates fundamental work in nonsmooth analysis, nonlinear partial differential equations, finite deformation theory, high pressure/high rate response, damage and failure mechanics, and computational mathematics. 

        Frictional Mechanics

 Modern composite materials

 Damage and fracture mechanics

 Penetration mechanics  

Nonconvex phenomena arise from large deformation mechanics, chaotic dynamical systems, buckling analysis and phase transitions, where the total potential energies are usually nonconvex.
Nonconvex mechanics cover many research fields of applications, such as:

 


New book on Nonsmooth and Nonconvex Mechanics:
Nonconvex/Nonsmooth Mechanics:  Modeling, Analysis and Numerical Methods
 

    By     David Y. Gao, Ray W. Ogden and G.E. Stavroulakis
    Kluwer Academic Publishers, Dordrecht/Boston
        Hardbound, ISBN 0-7923-6786-3
        February 2001, 516 pp.
        EUR 145.00 / USD 157.00 / GBP 99.00

The First International Symposium on Nonsmooth/Nonconvex Mechanics was held at  Virginia Tech, June 27-30, 1999.  The second one will be held in Greece, 2002, Click here for details 

 


Chaotic Systems   

Reason for chaos: Nonconvexity (multi-potential wells).
Examples:


New phenomena in chaotic systems
         1.
Meta-chaos:  Fig 1.  Fig. 2 (Chaos vase)
          2.
Trio-bifurcantion and trio-chaos: Life of a nonlinear beam vibration

Fig. 1,  Life of buckling beam

Fig. 2. First meta-buckling

Fig. 3. Second meta-buckling

Fig. 4. The third meta-buckling

Some movies about finite element simulations for dynamically post-buckling analysis of a rubber diaphragm created by my Ph.D. student Axinte Ionita:  

Movie 1(5.2MB)

Movie 2(2.32MB)

Movie 3(8.9MB)

Movie 4(3.26MB)