Thermal Tactile Perception

Using thermal tactile sensing mechanism based on semi-infinite body model, and combining with the advantages of maximum proportional controller, fuzzy and PID controller, a thermal tactile perception and reproduction experiment device (TTPRED) was designed based on the composite control strategy of threshold switching. The finger difference threshold measurement experiment of thermal tactile was carried out and the finger thermal tactile difference threshold was measured. The relationship between thermal tactile sensation and emotion based on temperature cues has been explored. The experiment results show that, the temperature control range of TTPRED is from -10℃ to 130℃, the temperature resolution and precision are 0.01℃ and ±0.1℃ respectively, the maximum heating or cooling rate is greater than 12℃, and the TTPRED can realize the temperature output of the specific waveform quickly and accurately. The experiment results of psychophysical experiment will provide the experimental foundations and technical support for the further study of thermal tactile perception and reproduction.

Thermal Tactile Perception

Using thermal tactile sensing mechanism based on semi-infinite body model, and combining with the advantages of maximum proportional controller, fuzzy and PID controller, a thermal tactile perception and reproduction experiment device (TTPRED) was designed based on the composite control strategy of threshold switching. The finger difference threshold measurement experiment of thermal tactile was carried out and the finger thermal tactile difference threshold was measured. The relationship between thermal tactile sensation and emotion based on temperature cues has been explored. The experiment results show that, the temperature control range of TTPRED is from -10℃ to 130℃, the temperature resolution and precision are 0.01℃ and ±0.1℃ respectively, the maximum heating or cooling rate is greater than 12℃, and the TTPRED can realize the temperature output of the specific waveform quickly and accurately. The experiment results of psychophysical experiment will provide the experimental foundations and technical support for the further study of thermal tactile perception and reproduction.

Nonlinear convolution integro-differential equation with variable coefficient

For an integro-differential equation of the convolution type defined on the half-line [0, ∞) with a power nonlinearity and variable coefficient, we use the weight metrics method to prove a global theorem on the existence and uniqueness of a solution in the cone of nonnegative functions in the space C[0, ∞). It is shown that the solution can be found by a successive approximation method of the Picard type; an estimate for the rate of convergence of the approximations is produced. We present sharp two-sided a-priori estimates for the solutions. These estimates enable us to construct a complete metric space which is invariant under the nonlinear convolution operator considered here and to prove that the equation induced by this operator has a unique solution in this space as well as in the class of all non-negative continuous functions vanishing at the origin. Such equations with operators of fractional calculus as the Riemann-Liouville, Erdélyi-Kober, Hadamard fractional integrals arise, in particular, when describing the process of propagation of shock waves in gas-filled pipes, solving the problem about heating a half-infinite body in a nonlinear heat-transfer process, considering models of population genetics, and elsewhere.

Research on the Algorithm for Composite Lining of Deep Buried Water Conveyance Tunnel

Composite lining of deep buried water conveyance tunnel for bearing high internal water pressure is a new type of applicable structure. However, up to date, no effective method is available to calculate the stress of the structure. In this paper, a simplified algorithm, which can be used to calculate the stress distribution of composite lining accurately but costs little computational resource, is proposed. This algorithm, which is based on the elastic theory, takes the effect of internal water pressure and surrounding rock on the composite lining into consideration, respectively. Then, the stress distribution of composite lining in infinite body is derived on the basis of Lame solution. Finally, a case study is followed by choosing a typical section of the Eastern Canal in Beijing of the South-to-North Water Diversion Project (SNWDP). This case study was analysed by using the simplified algorithm and verified by finite element method with ABAQUS. The results show that the stress distribution of composite lining can be obtained quickly and accurately with the simplified algorithm, which can provide a reference for other engineering designs.

Analytical Study of the Process of Dissolution of Silicon from a Modifier Particle

The process of dissolution of a particle of a ferrosilicon modifier in a cast iron melt is considered, taking into account such a physical analogy as the distribution of heat from a point source in space (an infinite body).

Deformation Mechanism and Control Technology of the Surrounding Rock of the Floor Roadway under the Influence of Mining

Deformation and failure mechanism of the surrounding rock of the floor roadway under the influence of working face mining is complicated, and roadway control is difficult. The floor roadway of the 11123 working face in Pan’er Mine is taken as the research object of this study based on semi-infinite body theory of elastic mechanics to establish a mechanical model along the advancing direction of the working face and derive the stress expression of any point in the affected area of floor mining. According to the theoretical results, effective reinforcement and support schemes are then proposed. FLAC3D numerical simulation analyzes the stress and deformation of the surrounding rock of the floor roadway before and after the reinforcement. The numerical simulation results showed that (1) mining abutment pressure of the overlying working face forms a certain range of stress concentration on the roof and two sides of the roadway and will cause deformation and damage to the floor roadway and (2) overall bearing capacity of the surrounding rock of the roadway is significantly improved, and surface displacement of the floor roadway is reduced by 64 mm through the reinforcement and support of the floor roadway. On-site monitoring data of the floor roadway in the 11123 working face of Pan’er Mine showed that the maximum displacement of the roadway roof and two sides is controlled at approximately 80 mm, and the surrounding rock deformation of the roadway is appropriately controlled to meet the needs of safe production.

Multi-Layer Transient Heat Conduction Involving Perfectly-Conducting Solids

Boundary conditions of high kinds (fourth and sixth kind) as defined by Carslaw and Jaeger are used in this work to model the thermal behavior of perfect conductors when involved in multi-layer transient heat conduction problems. In detail, two- and three-layer configurations are analyzed. In the former, a thin layer modeled as a lumped body is subject to a surface heat flux on the front side while it is in perfect (fourth kind) or in imperfect (sixth kind) thermal contact with a semi-infinite or finite body on the back side. When dealing with a semi-infinite body in imperfect contact, the temperature solution is derived by means of the Laplace transform method. Green’s function approach is also used but for solving the companion case of a finite body in perfect contact with the thin film. In the latter, a thin layer with internal heat generation is located between two semi-infinite or finite bodies in perfect/imperfect contact. For the sake of thermal symmetry, such a three-layer structure reduces to a two-layer configuration. Results are given in both tabular and graphical forms and show the effect of heat capacity and thermal resistance on the temperature distribution of conductive layers.

Thermoelastic Processes by a Continuous Heat Source Line in an Infinite Solid via Moore–Gibson–Thompson Thermoelasticity

Many attempts have been made to investigate the classical heat transfer of Fourier, and a number of improvements have been implemented. In this work, we consider a novel thermoelasticity model based on the Moore–Gibson–Thompson equation in cases where some of these models fail to be positive. This thermomechanical model has been constructed in combination with a hyperbolic partial differential equation for the variation of the displacement field and a parabolic differential equation for the temperature increment. The presented model is applied to investigate the wave propagation in an isotropic and infinite body subjected to a continuous thermal line source. To solve this problem, together with Laplace and Hankel transform methods, the potential function approach has been used. Laplace and Hankel inverse transformations are used to find solutions to different physical fields in the space–time domain. The problem is validated by calculating the numerical calculations of the physical fields for a given material. The numerical and theoretical results of other thermoelastic models have been compared with those described previously.