In this contribution, a generalized Cam clay model for cohesive soil materials is introduced. A new formulation not only suppresses evolution of excessive failure stresses and dilatancy rate, but also allows for the reduction of поп-realistic softening behavior of overconsolidated soils predicted when adopting the formulation of classical Cam clay model. More realistic response of the soil is achieved by introducing a new yield function in the dilatation (supercritical or dry) domain, i.e. for OCR > 2. Further, the dependency of the yield function on the Lode angle is adopted and non-associated flow rule is assumed. Finally, the reduction of hardening modulus is shown in comparison to the classical Cam clay model formulation. and Obsahuje seznam literatury
This paper is concerned with the functional observer design for a class of Multi-Input Multi-Output discrete-time systems with mixed time-varying delays. Firstly, using the Lyapunov-Krasovskii functional approach, we design the parameters of the delay-dependent observer. We establish the sufficient conditions to guarantee the exponential stability of functional observer error system. In addition, for design purposes, delay-dependent sufficient conditions are proposed in terms of matrix inequalities to guarantee that the functional observer error system is exponentially stable. Secondly, we presented the sufficient conditions of the existence of internal-delay independent functional observer to ensure the estimated error system is asymptotically stable. Furthermore, some sufficient conditions are obtained to guarantee that the internal-delay independent functional observer error system is exponentially stable. Finally, simulation examples are provided to demonstrate the effectiveness of the proposed method.