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The hydro-mechanical behaviour of unsaturated soils is often highly influenced by the microstructure; therefore, it can be beneficial to consider the effect of microstructure in a hydro-mechanical constitutive model. This paper considers the use of a microstructure-related model that adopts the effective degree of saturation as a microstructural index. The model can be used to reproduce the hydro-mechanical behaviour while the effect of the microstructure is considered. For comparison, a non-microstructuredependent model is also employed. The models are applied to simulate the behaviour of two different soilsand a comparison of the models’ performance in simulating triaxial test behaviour is made. Based on the comparison with experimental results and the non-microstructure-dependent model, it can be concluded thatthe adoption of the effective degree of saturation is beneficial to studying the hydro-mechanical behaviour of unsaturated soils affected by the microstructure.

In actual work, the system parameters of the robot joints will change in real time or cannot be measured, and the coupling relationship between the various subsystems and the existence of modeling errors make the system model difficult to determine. Based on such problems, a neural network observation is proposed Decentralized control method for robot joints of the robot. In the actual control of the manipulator, firstly, the model of each joint subsystem is established by the decentralized control theory, and the nonlinear function approximation ability of the neural network is used to approach the uncertain part of the manipulator subsystem online through input and output data. The design observer can estimate the state of the system, and use the estimated state to design a sliding mode controller to dynamically estimate and compensate the unknown model dynamics of each independent joint, and realize the self-control of the system when the speed information and model information are unknown. Adaptive control greatly enhances the robustness and adaptability of the robotic arm system. Finally, the stability criterion of the neural network observer and the sliding mode controller is given by the Lyapunov function method, and the simulation results prove the effectiveness of the design method.

This article presents a bounding surface model for unsaturated soils by using skeleton stress and bonding variable based on microcosmic pore structure as constitutive variables. A Hydraulic hysteresis soil-water characteristic curve model considering deformation and hydraulic hysteresis is combined to achieve hydraulic coupling. The proposed model can capture the change of the inter-particles bonding effect in the deformation process of unsaturated soils and accurately predict the hydraulic mechanical behavior of unsaturated soils under complicated loading paths and wetting-drying cycles. The validity of the proposed model is confirmed by the results of unsaturated isotropic compression tests, wetting-drying cycles tests and unsaturated triaxial shear tests reported in the literature.