Advanced Materials Research Vols. 1025-1026

Abstract: This paper presents finite element modelling of fretting wear under partial slip conditions using combined isotropic-kinematic hardening plasticity model with the emphasized to investigate the cyclic-plasticity behaviour predicted under fretting condition. The model is based on two-dimensional (2D) cylinder-on-flat contact configuration of titanium alloy, Ti-6Al-4V. A number of wear profiles at specific number of wear cycle (6000^th, 60000^th, 150000^th and 300000^th) are simulated. Contact pressure, tangential stress, shear stress, equivalent plastic strain, tangential plastic strain and also shear plastic strain are gathered and analysed. It is found that the plastic strain response of the combined isotropic-kinematic hardening plasticity model is slightly higher compare to linear kinematic hardening plasticity model [1].

Abstract: Coordinate Measuring Machines (CMM's) have attributes to provide results with accuracy and repeatability in measurements, so they are considered equipment with potential for application in industrial environments, specifically in inspection processes. However, as in a machine tools the knowledge of the errors in CMM is needed and allows applying techniques of error compensation. This study aimed to develop a mathematical model of the kinematic errors of a bridge type CMM in "X", "Y" and "Z" directions. Modeling of the errors was accomplished using coordinate transformations applied to the rigid body kinematics; the method of the homogeneous transformation was used for the development of the model. The position and angular errors for the three axes of CMM, in addition to errors related to the absence of orthogonality between them were equated. This study allowed to conclude that modeling of errors applied to CMM allied to calibration is able to evaluate the metrological performance of equipment with displacement on guides, thus is possible to use this technique as error budget analysis in machines.

Abstract: In the paper separation methods of organic part from oil sands were investigated at experimantally. For the determination of organic part (liquid fraction) of oil sands the extraction methods was used in Soxhlet apparatus by solvent. Thermal processing was carried out with a monotonic heating of oil sands from room temperature to 560 ⁰C. As showing results, organic part of Beke oil sands studied by extraction method were 12.0 wt.%. Thermal processing results showed, that the organic part of Beke oil sands were 9.6 wt.%. Physical and mechanical characteristics of liquid fraction are established by standard methods.

Abstract: This study aimed to investigate the influence of storage time (0, 48 hours) of Pinus elliottii pieces and the tests to obtaining modulus of elasticity (static bending and transversal vibration) in glued laminated timber beams, produced with resorcinol based adhesive and 0.8 MPa compaction pressure. After pieces were properly prepared, part of them was used in immediate three manufacturing glulam beams, tested after adhesive cure, and part stored for 48 hours under a roof with a temperature of 25°C and relative humidity of 60% for subsequent manufacturing and testing three other glulam beams. Results of analysis of variance (ANOVA) revealed that the storage period was significant influence in modulus of elasticity obtained in static bending test (8% reduction from 0 to 48 hours). This not occurred with modulus of elasticity obtained by transversal vibration test (no significant influence). ANOVA results showed equivalence of means in both test procedures. New researches ire needed to better understand the investigated phenomenon, using new wood species, other storage conditions and a great number of samples.

Abstract: The article describes and analyzes the process of mass concrete casting and crack problems during the period of construction. The article illustrates the necessity of crack control for mass concrete structures and introduces the present application situation of commercial software used to analyse the temperature field and stress field. Combining the engineering practice, the article sums up the measures to deal with hydraulic mass concrete structure cracks and the application situation of various methods. Then the article puts forward the future research direction to solve the problem of hydraulic mass concrete crack.

Abstract: Basing on the ANSYS finite element analysis, the research takes a flat type tower crane boom on the ear plate and upper chord (round steel) of the connection as example. On the shape of the ear plate, welding form, round steel insert depth and the thickness of the ear plate concrete structure and parameter design are analyzed. Comparing the mechanical properties of bearing model, and then to discuss the ear plate and round steel joint stress concentration problem.

Abstract: The article deals with numerical analysis of nonlinear vibration isolation system free oscillations. According to the latest recommendations [1], vibration isolation of precision equipment should be effective over the 1 – 100 Hz range [2]. This fact sets a challenge to develop a sub-herz vibration isolator. Such vibration isolators with 0.5 Hz natural frequency have been developed in latest works [3,4]. For mathematical representation of such a dynamical system, elastic characteristic should be approximated with a polynomial. In this paper, we consider the approximation of elastic characteristic by means of 5^th and 7^th order polynomials. This leads to numerical solution of nonlinear dynamic equations. We construct the solution of such equation on the phase plane and determine equilibrium points. The stability of the equilibrium points is investigated using linearization technique. The law of the isolated mass oscillations is derived from numerical solution of the dynamic equation by means of Dorman – Prince 4(5) and 8(7) solver and the system’s natural frequencies are calculated using the FFT technique.

Abstract: Through this study, equipment was developed which could work large size stones into linear and curve shaped cutting planes and cut polygonal shaped stones during the lapping and semi-finishing works which are pre-tasks to manufacture the large size building column or large size stone statue which is installed in the temple. The best is to read these instructions and follow the outline of this text. Safety of equipment could be secured using design program and structure interpreting program and productivity could be improved by reducing the required manpower and working time for rough grinding and semi-finishing works through positioning control module. This technology is expected to be utilized in manufacturing various stone equipments by applying the working path generation and oil pressure technologies as the type of NC work equipments as well as in future working area.

Abstract: The distinctive paper is devoted to verification of discrete-continual finite element method (DCFEM) for two-dimensional problems of structural analysis. Formulation of the problem for deep beam with constant physical and geometrical parameters along so-called its basic direction, solutions obtained by DCFEM and finite element method (FEM) /with the use of ANSYS Mechanical/, their comparison are presented. It was confirmed that DCFEM is more effective in the most critical, vital, potentially dangerous areas of structure in terms of fracture (areas of the so-called edge effects), where some components of solution are rapidly changing functions and their rate of change in many cases can’t be adequately taken into account by the standard finite element method.

Abstract: This paper continues series of papers devoted to verification of discrete-continual finite element method (DCFEM) for two-dimensional problems of structural analysis. Formulation of the problem for deep beam with piecewise constant physical and geometrical parameters along so-called its basic direction, solutions obtained by DCFEM and finite element method (FEM) /with the use of ANSYS Mechanical/, their comparison are presented. It was confirmed that DCFEM is more effective in the most critical, vital, potentially dangerous areas of structure in terms of fracture (areas of the so-called edge effects), where some components of solution are rapidly changing functions and their rate of change in many cases can’t be adequately taken into account by the standard FEM.