Papers by Sebastien Corner
Sensitivity analysis of multibody systems computes the derivatives of general cost functions that... more Sensitivity analysis of multibody systems computes the derivatives of general cost functions that depend on the system solution with respect to parameters or initial conditions. This work develops adjoint sensitivity analysis for hybrid multibody dynamic systems. Hybrid systems are characterized by trajectories that are piecewise continuous in time, with finitely-many discontinuities being caused by events such as elastic/inelastic impacts or sudden changes in constraints. The corresponding direct and adjoint sensitivity variables are also discontinuous at the time of events. The framework discussed herein uses a jump sensitivity matrix to relate the jump conditions for the direct and adjoint sensitivities before and after the time event, and provides analytical jump equations for the adjoint variables. The theoretical framework for sensitivities for hybrid systems is validated on a five-bar mechanism with non-smooth contacts.
This research introduces a proposed model for predicting tilting angle and limit states of single... more This research introduces a proposed model for predicting tilting angle and limit states of single-fastened cold-formed steel-to-steel shear connections. Predictions are validated through an experimental study considering ply configuration and a single Hex #10 -washer head fastener, centered in a 102 mm by 102 mm three boundary window. The fastener tilting angle is captured using an automated, optical non-contact measurement procedure. The results are used to identify cold-formed steel shear connection deformation as load progresses, including tilting, bearing, and combined tilting bearing at the plies and thread tension, shear and bearing fastener failure. Results shows that fastener tilting plays a kinematic affect for the connection. Fastener tilting is predicted in function of ply thickness and fastener pitch. Local ply bending deformation is reported to be the main deformation of the connection during fastener tilting. While fastener bending and shear failure occurred if the fas...
This dissertation provides a complete mathematical framework to compute the sensitivities with re... more This dissertation provides a complete mathematical framework to compute the sensitivities with respect to system parameters for any second order hybrid Ordinary Di erential Equation (ODE) and rank 1 and 3 Di erential Algebraic Equation (DAE) systems. The hybrid system is characterized by discontinuities in the velocity state variables due to an impulsive forces at the time of event. At the time of event, such system may also exhibit a change in the equations of motion or in the kinematic constraints. The analytical methodology that solves the sensitivities for hybrid systems is structured based on jumping conditions for both, the velocity state variables and the sensitivity matrix. The proposed analytical approach is then benchmarked against a known numerical method. The mathematical framework is extended to compute sensitivities of the states of the model and of the general cost function with respect to model parameters for both, unconstrained and constrained, hybrid mechanical sys...
Multibody System Dynamics, 2020
Sensitivity analysis of multibody systems computes the derivatives of general cost functions that... more Sensitivity analysis of multibody systems computes the derivatives of general cost functions that depend on the system solution with respect to parameters or initial conditions. This work develops adjoint sensitivity analysis for hybrid multibody dynamic systems. Hybrid systems are characterized by trajectories that are piecewise continuous in time, with finitely-many discontinuities being caused by events such as elastic/inelastic impacts or sudden changes in constraints. The corresponding direct and adjoint sensitivity variables are also discontinuous at the time of events. The framework discussed herein uses a jump sensitivity matrix to relate the jump conditions for the direct and adjoint sensitivities before and after the time event, and provides analytical jump equations for the adjoint variables. The theoretical framework for sensitivities for hybrid systems is validated on a five-bar mechanism with non-smooth contacts.
Http Www Pobot Org, Jan 20, 2011
Nonlinear Analysis: Hybrid Systems, 2019
This paper provides an analytical methodology to compute the sensitivities with respect to system... more This paper provides an analytical methodology to compute the sensitivities with respect to system parameters for any second order hybrid Ordinary Differential Equation (ODE) system. The hybrid ODE system is characterized by discontinuities in the velocity state variables due to an impulsive jump caused by an instantaneous impact in the motion of the system. The analytical methodology that solves this problem is structured based on jumping conditions for both the state variables and the sensitivities matrix. The proposed analytical approach is of the benchmarked against a numerical method.
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Papers by Sebastien Corner