A general theory is developed for the mechanical expression of agrofood, cellular materials. The so-called, Liquid-containing biporous particles expression model considers liquid transfer within a network of three different volumes: extraparticle, extracellular and intracellular volumes. The system of partial differential equations i s solved for the expression under constant pressure, allowing calculation of the total layer settlement, as well as the deformation of extraparticle, extracellular and intracellular volumes. The model is able to predict the behavior of four different steps in the consolidation stage: the primary deformation and the creep deformation of extraparticle volume, and the deformation and deliquoring of both extracellular and intracellular volumes. The model is applied to the hydraulic pressing of rapeseeds. The theoretical model agrees well with experimental data for the overall range of pressing time.pression of clay cakes. This is conceptually close to Terzaghi's theory, but it accounts for two periods of consolidation: the primary and the creep (or secondary) consolidations (Gibson and Lo, 1961;Florin, 1959). Shirato et al. (1974, 1978, 1986), and Rebouillat et al. (1985 have used creep consolidation models for both constant pressure and rate, and varying pressure and rate.The mechanisms for expression of mineral cakes and cellular materials are basically different. With mineral cakes, the cake is initially saturated by the liquid, and cake deformation depends only on the reorientation of individual, incompressible particles within the cake. With biological and cellular materials, the expression mechanism is much more complex. The liquid is stored mainly in cells; some gas may al:jo be present in the cellular structure. During expression the air dissipation and the cell rupture significantly modify the cake compressibility. Also, intraparticle and extraparticle volumes are compressible. Thus, the reorientation of the liquid-contaking particles and the evolution of the particle microstructure affect the local stress gradients, and consequently the expression performances. Although the mechanical expression of biological and cellular materials obeys a very complex mechanism, the authors have used the aforementioned theory and models, under constant pressure (Austmeyer, 1987;Sivala et al.
The problem of constructing movements with manipulators with five degrees of freedom when capturing a cylindrical part, transferring it to a given position for the process of connecting parts are considered. Cyclograms of movement of manipulators during assembly are constructed.
The study focuses on a two-handed robot with twelve degrees of freedom, six for each arm, and gives an example of calculating generalized coordinates for the two-armed robot limbs at their joint manipulation. The initial data for obtaining generalized coordinates are represented by the location of the work object, which is a cube. When solving the problem, the last arm links reach the faces of the work object with a given orientation. To obtain generalized coordinates, we used a hierarchical approach, which is based on an algorithm for solving the inverse problem of kinematics, and developed a control flow chart. The values ??of generalized robot coordinates were obtained for each location of the object of work, taking into account the kinematic constraints in the joints of the robot actuator. Findings of research show that it is possible to obtain generalized coordinates for the coordinated movement of the robot actuators with tree-like kinematic scheme.
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