Jean-François Antoine

Approximate analytical model for hertzian elliptical contact problems

In rolling bearing analysis Hertzian contact theory is used to compute local contact stiffness. This theory does not have a closed form analytical solution and requires numerical calculations to obtain results. Using approximations of elliptical functions and with a mathematical study of Hertzian results, an empirical explicit formulation is proposed in this paper and allows us to obtain the dimensions, the displacement, and the contact stress with at least 0.003% precision and it can be applied to a large range of ellipticity of the contact surface.

A product functional modelling approach based on the energy flow by using characteristics-properties modelling

ABSTRACT The main objective in designing a product is to satisfy the required needs. So, the designer aims to design the product’s structure based on the required function of the product. Therefore, in the design process, the link between the functional requirement and the physical structure has to be assured. This paper proposes an approach to help the designer in transition from function to structure to assure this link. This approach uses energy flow modelling to model the system’s behaviour in the framework of characteristics-properties modelling (CPM). It is composed of a multi-level modelling approach with two concurrent, interlinked modelling domains: functional and structural. By zigzagging between these two domains in each level of the decomposition, a quantitative model of the product is determined using CPM. The result shows the effective modifiable parameters (or required structure) of the product to satisfy the required function. So, it can be used to design a new product as well as analysing and optimising an existing product.

Optimization of the design for a switched reluctance drive controlled by trapezoidal shaped currents

This papers deals with an original way to optimize the pre-designing of a switched reluctance motor (SRM). The analytic equations are treated to make the complete design depend only on two parameters. Particular attention is paid to high rotational speeds and the hypotheses they induce on the design. The hypothesis of a current control is assumed and the methodology tackles the design problem through the angle of the power electronics constraints. The specific problem set by the trapezoidal current shape is highlighted, as much as the direct constraints induced on the motor shape design. Mechanical and thermal limitations, modeled in function of the main material characteristics are deterministically taken into account. An optimization is finally performed, reducing the losses of the motor in terms of the mere lasting parameter.

Workspace Analysis of a 4 Cable-Driven Spatial Parallel Robot

This paper presents the static equilibrium workspace of an under-constrained cable-driven robot with four cables taking into account the forces and the moments due to the forces acting on the moving platform. The problem is formulated as a non-linear optimization problem with maintaining static equilibrium as the objective function. The simulations are done using MATLAB. The maximum force on the cables and tilting angle of the platform are used to define the feasible static equilibrium workspace and the results obtained are used to finalize the design of the collaborative cable-driven robot to be installed in existing production lines for the agile handling of parts in a manufacturing industry.