Modelica is an object-oriented language for modeling of large and heterogeneous physical systems. Typical applications include mechatronic models in automotive and aerospace applications involving mechanical, electrical and hydraulic subsystems as well as control systems. Modeling of an ideal diode and Coulomb friction is discussed to illustrate the unique hybrid features of Modelica. The langu...

We consider a mathematical model which describes the frictional unilateral contact between a thermo-piezoelectric body and a rigid electrically conductive foundation. The thermo-piezoelectric constitutive law is assumed to be nonlinear and the contact is modeled with the Signorini condition, the nonlocal Coulomb friction law with slip dependent friction coefficient and the regularized electrica...

Deformable systems that rely on dry friction for their proper functioning are widely found in many engineering applications such as bolted components, railway ballast. The design of these systems is usually considered from static point of view and employing Coulomb model of friction. This paper studies the effects of dynamic loading on the behavior of a two dimensional system by finite element ...

One of the great challenges in the processing of materials using Equal Channel Angular Pressing (ECAP) is the high forming forces required to produce large shear deformation in the material. Researchers show that the friction forces between the die and the sample constitute a great part of the total forming forces. Recently, ultrasonic vibrations are successfully implemented into the ECAP proce...

In this paper, we deal with the problem of time-optimal trajectory planning and feedforward controls for robotic manipulators along predetermined geometric paths. We propose a convex relaxation to generate time-optimal trajectories and feedforward controls that are dynamically feasible with respect to the complete nonlinear dynamic model, considering both Coulomb friction and viscous friction. ...

This paper studies the high-performance robust motion control of machine tools. The newly proposed adaptive robust control (ARC) is applied to make the resulting closed-loop system robust to model uncertainties, instead of the disturbance observer (DOB) design previously tested by many researchers. Compared to DOB, the proposed ARC has a better tracking performance and transient in the presence...

Previous researches on the constant ductility inelastic displacement ratio spectra (\({C}_{\upmu }\)) of self-centering structures have been conducted based typical flag-shaped (FS) model. However, arising shape-memory-alloy-friction (SMAFSs) own their specialized force–displacement relationship different from FS In this research, a hybrid model composed and Coulomb friction is employed an effi...

The variable stiffness exosuit has great potential for human augmentation and medical applications. However, the model of mechanism in exosuits is far from satisfactory accurate prediction control friction force. This paper presents a lower limb exosuit, verifies its performance, identifies applicability. force was established by Coulomb hypothesis. equivalent coefficient, which core parameter ...

An analytical model for asymmetric rolling is presented, which includes asymmetry in roll friction, roll size and roll speed, for a rigid, perfectly plastic thin sheet deformed with Coulomb friction. This model is solved asymptotically, based on the systematic assumptions that both the roll gap aspect ratio and the friction coefficient are small. While the leading order solution is shown to be ...