Papers by Keyword: Mechanical Load

Abstract: The article considers and analyses the methods by which it is possible to carry out research to determine the fire resistance of elements of steel frames of industrial buildings. It is determined that it is expedient to use the means of computational fluid dynamics, which has no limitations due to the high cost, complexity, environmental friendliness and complexity in comparison with real experiments. In order to conduct the most reliable computational experiments, mathematical models of temperature and mechanical reaction to the thermal effect of fire were created, taking into account the equations of thermal conductivity, systems of differential equations of stress-strain state of solids in their numerical implementation based on the finite element method. The solution of mathematical models was carried out using computational fluid dynamics, which describes the process of heat and mass transfer in test fire furnaces during the determination of fire resistance of steel structures. According to the results of computational experiments it is shown that the limiting state of loss of bearing capacity of vertical and horizontal structures occurs due to the formation of a zone of plastic deformations taking into account the associative theory of plasticity. According to the results of computational experiments, the dependence of the limit of fire resistance on the level of applied load to structures, which is close to linear, was revealed. Based on the obtained dependences and the corresponding graphs, a technique is developed based on the use of maximum deformations of the elements with the corresponding fixation of the limit state on the loss of fire resistance in terms of bearing capacity by bending this curve.

Abstract: Bonded fibre reinforced polymers (FRP) have been found to be an efficient method for improving the lifespan of fatigued metallic structures and have attracted much research attention. Steel beams can be reinforced in flexure using FRP plates that rely on adhesively bond. In such plated structures, shear forces are developed in the bonded joint and these will be transferred to FRP plate via the adhesion technique, thus, the interfacial stresses will progress consequently, and the debonding may occurs at the plate ends due to high values of interfacial stresses. This original research leads us to predict the interfacial stresses by a numerical study, using a finite element model under ANSYS software and coupling effects of mechanical and thermal loads with fibre orientation. Finally, a parametric analysis is used to identify effects of various geometrical and material properties on the magnitude of stresses values. This analysis is helpful because of the adaptation in the modelling process. It is shown that the bearing capacity of the adhesive joint is significantly influenced not only by the strength model, but also, by the shear modulus, elastic modulus of FRP and the other parameters..

Abstract: The finite element analysis was carried out on the piston of WWD - 0.8/10 type air compressor under the action of mechanical load stress and deformation.Using three-dimensional modeling software Solidworks to establish a simplified geometric model of piston in air compressor ,Transform the model built in the three dimensional finite element analysis software into the finite element model for analysis,Determine the method of the piston by the mechanical load and boundary conditions,Completed the stress analysis and deformation analysis of the piston under the mechanical load ,The results of analysis of the piston design optimization has important reference value.

Abstract: MAN Diesel’s 6S50MC-C two-stroke marine diesel engine is researched in this paper. The intensity under the effect of thermal load, mechanical load and coupled loads are analyzed. As the boundary conditions of the temperature field distribution, the mean temperature and the mean heat transfer coefficient are calculated firstly. Based on the temperature field, the thermal intensity is obtained in ANSYS. Then the study analyzes the stress and the strain distribution when the mechanical load and the coupled loads are applied. Through the analysis of different loads, the maximum stress is 696MPa in thermal load, 191MPa in mechanical load and 659MPa in coupled loads. The maximum deformation is 1.011mm in thermal load, 0.147mm in mechanical and 1.022mm in coupled loads. The intensity meets the design requirement. The stress concentration and the deformation of the piston crown mainly are generated by the thermal load. To reduce the destructive effect of thermal, it requests enhancing cooling and warming up the main engine.

Abstract: MAN Diesels 6S50MC-C disel is a two-stroke marine diesel engine. Preload of the exhaust valve component is applied in four bolts. The preload of bolts can improve the fatigue strength of the exhaust component. In addition, the bolt pretension ensure the sealing in the maximum firing pressure. Using of simulation method, the displacement and deformation of exhaust valve component are analyzed when the maximum firing pressure and preload are applied. By analysis of the deformation of the exhaust valve housing under different preload force, the deformation of exhaust valve housing increase with the increaseing of preload. The maximum total deformation is 0.40mm in the preload of 720KN. The maximum deformation occurs in the region near the bolt in the side of exhaust gas outlet. The deformation in the direction of Y-axis of exhaust valve housing is along the Y-axis opposite direction when the preload is greater than 540KN. This indicates that the exhaust valve seal well. The sealing and deformation of the exhaust valve component meets the desgin requirement.

Abstract: The results of experimental investigations of unreinforced and reinforced modified concrete under monotonically increasing load until fracture, simple short-term load at the limit of capacity and repeated load with continuous loading and release rate should be presented. The modification of the concretes was approached in two ways: the variation of the aggregates and the modification of the binder phase with thermoplastic polymers. Of particular interest were the effects of the modifications on the strength properties and the deformation behavior under short-term load. The observed changes in the hardened concrete properties and the non-linear relation between the elastic and inelastic proportions of deformation indicate that such modifications affect the deformation and fracture behavior of concrete significantly. Therefore they have to be accounted for the analysis of capacity and suitability. In addition to the evaluation of the load-dependent deformation behavior, the established approaches to describe the structural state areas are developed further. Therewith, the transitions between the areas can be determined accurately and the dimension of the areas can be quantified. As a result the changes caused by modifications could be compared more precisely.

Abstract: In this paper, the model of the piston is founded by use of UG, and then joined in the ANSYS, applied the Multiphysics module and static structuer analysis function, we can count the stress field of the piston and accomplish the evaluate of the mechanical load.

Abstract: Chloride ion penetration and freezing and thawing damage are the two main factors that affect the durability of concrete structures. Through the chloride ion penetration test and freezing and thawing test of concrete specimens after tensile and compressive loading, the influence of load-induced damage on the long-term durability of concrete was studied. The results showed that the apparent chloride diffusion coefficient of concrete increased by 6.4% and 34%, and the surface chloride concentration increased 10% and 40%, respectively, both of which showed the "negative effect" when the uniaxial tensile load level reached the 65% and 75% of the ultimate capacity. However, with the increasing uniaxial compressive load level, the impact on the frost resistance of concrete experienced a transformation from the "positive effect" to the "negative effect".

Abstract: In this paper, the model of the engine connection rod is founded by use of UG, and then joined in the ANSYS, applied the Multiphysics module and static structuer analysis function, we can count the stress field of the connection rod and accomplish the evaluate of the mechanical load.

Abstract: A carbonation model of reinforced concrete structures subjected to mechanical load based on experimental work is proposed in the paper. Correspondingly, a series of reliability analysis and service life prediction is carried out and reasonable results are acquired. Besides the effect of concrete cover, it indicates that mechanical load impacts the reliability and service life of the reinforced concrete structures significantly through example calculation. In the case of concrete cover of 40mm, the service life is shortened nearly half under a tensile load of 60% while the service life is lengthened 30% under a compressive load of 30%. In service life design or long term performance assessment, more work should be done with the consideration of the mechanical load effect.