Volume 37 - 2022


1. Implantation by an implicit approach of an elastoplastic behaviour law in the finite element cast3m code

Christian Fokam ; Franklin Kanko ; Rolland Djomi ; Bienvenu Kenmeugne ; Kanmogne Abraham ; Guy Ntamack.
This paper is dedicated to the implementation of a law of mechanical behavior in the finite element software Cast3M using an open source code generator named Mfront. To do so, an elastoplastic behaviour model has been chosen from existing laws in the literature. Following an implicit discretization, a hardware library corresponding to the isotropic and kinematic strain-hardening model is generated using Mfront. The UMAT computer interface is used to build the library in Cast3M. A validation of the approach has been carried out by comparing the numerical results obtained with the generated hardware library and the equivalent pre-existing library in Cast3M. Simulations in the case of a tensile bar and a perforated plate show almost identical results

2. Assessing Maintenance of Arboviruses in Nature via Aedes Mosquitoes by Positive semigroup

Papa Ibrahima Ndiaye ; Mamadou Ndongo.
For more than one century, Aedes species are supposed to be a reservoir in dengue, yellow fever, rift valley fever and west nile viruses transmission. In this article, we study an infinite dimension ordinary differential equations system that models arbovirus vertical transmission in \textit{Aedes} mosquito. Relying of the positive semigroup theory, we show that the model is well-posed and compute a threshold parameter known as the basic reproduction ratio $R0$. This parameter describes "the average rate of secondary new cases of infected adult females from emergences in a breeding habitat that are produced by an infected adult female via transovarial transmission during its lifetime." In addition, we prove that the solution of the model goes to zero asymptotically if R0<1$, else it has the property of balanced exponential growth. Finally, a climate-environment effects Index on model parameters and a diagram depicting the conditions of arboviruses persistence via Aedes in nature is derived.