Wear behavior of tool flank in the side milling of Ti6Al4V: An analytical model and experimental validation

Due to the poor machinability of Ti6Al4V material, the cutting tool can easily suffer flank wear during the process of high-speed side milling, which reduces the tool life as well as the surface integrity of workpiece. Further, an effective method for predicting the flank wear of end mill during side milling of Ti6Al4V is lacking in the existing literature, which makes it difficult to improve the productivity of the overall process. To this end, in this study, a flank wear prediction model is constructed based on three main mechanisms: abrasive wear, adhesive wear, and diffusive wear. Subsequently, a normal stress model and temperature field model of wear land on the flank of end mill are established. Finally, these two models are incorporated in the flank wear model to obtain the variation rate of wear land width, which is regarded as a criterion to evaluate the reliability of the proposed flank wear prediction model of side mill. The prediction results are found to be in excellent agreement with the experimental results, which verifies the high prediction accuracy of the proposed model. Overall, this model can serve as a useful theoretical basis for the rational selection of tool geometry and cutting parameters.

Calculation of transient temperature and rated capacity of three-phase induction motor under different working systems

This paper aims to propose a method to determine the temperature rise and rated capacity of induction motors under different working systems. A dynamic mathematical model, a 3D temperature field model, and finite element method are used to analyze the electromagnetic loss and transient temperature rise, respectively. The influence of the motor starting process on the temperature rise is taken into account, which resolves the complex loading of transient heat source. The maximum allowable running times for the motor operating with different overloads are determined. The relationship between the motor output power and the allowable running time is obtained, and it provides a basis to determine the rated capacity of motor under S2 working system. The relationship between the motor output power and the temperature rise under different load duration rates is also obtained and provides reasonable evidence to determine the rated capacity of the motor under S3-working system.

Temperature Effect on Stability of Clamped–Clamped Composite Annular Plate with Damages

The paper presents the response of a three-layered annular plate with different damaged laminate facings to the action of the static or dynamic temperature field model. Various damages of laminate, composite facings change the plate structure reaction under the temperature fields. Obtained results indicate practical meaning of analyses in failure diagnostic process. The thermal sensitivity of two kinds of plate structures, undamaged and damaged, offers both new practical and scientific possibilities in evaluation of the plate behavior. The relations between macro-damage, i.e., the buckling of the plate structure and micro-damages of plate layers subjected to temperature gradient, are shown. The numerical solution is proposed as the most effective in examinations of the various transversally symmetrical and asymmetrical plate structures with a different rate of damages. The graphical distribution of changes in values of static and dynamic critical loads illustrate the process of structural damaging during its exploitation. They have practical importance in the evaluation of the structure capacity. The knowledge of the effect of laminate degradation process on plate buckling phenomenon located in thermal environment complements previous investigations and designates complex, multi-parameter problems as having scientifically new elements.

Numerical Calculation About Influence of Crystallizer Structure on the Stress Evolution Process of Horizontal Continuous Casting of Copper Tubes

The horizontal continuous casting plays a key role in the production of inner grooved copper tubes. In order to improve the accuracy of the temperature field model of the copper tubes horizontal continuous casting process, the model heat transfer coefficient was validated through temperature measurement experiment of graphite crystallizer. The finite element model of stress field evolution was established, based on considering the temperature and microstructure changes. It was found that tensile stress was generated in the outer layer of the casting billet and compressive stress was generated in the inner layer, when the casting billet entered the primary cooling zone. The paper investigated the mechanism of the liquid inlet number and shape on the microstructure and stress distribution after the casting billet was solidified. When the number of liquid inlets was 6, the ratio of the semimajor axis of ellipsoid to the short semi-axis was 3:2 and the backward tilt angle was 10°, the equivalent stress value of the casting billet was smaller and the grains were dense and uniform. This paper promotes the research of horizontal continuous casting process and provides measurable reference for improving the quality of casting billet in the further.

Multi-Field Collaborative of Oil-Immersed Transformer for Distributed Energy Resources Temperature Rise Considering the Influence of Heat Transfer Oil

The current calculation method of fluid–structure interaction (FSI) has a defect for oilimmersed transformers for distributed energy resources (DERs). In order to solve this problem, a calculation method is proposed for the temperature rise of oil-immersed transformers in this article. The vibration of insulating oil is considered in this method. Different from the temperature field model established by FSI, the effect of insulating oil vibration on the temperature field is considered. The structure field is introduced to establish the insulating oil vibration model. The temperature field correction coefficient is introduced by coupling the insulating oil vibration and the natural convection of the insulating oil. The result shows that compared with FSI, the results of the calculation method in this study are consistent with the experiment, and the temperature field distribution in the oil-immersed transformer can be calculated more accurately.

Analysis and evaluation of temperature field and experiment for magnetorheological fluid testing devices

When a large amount of heat is produced during the operation of a MRF (magnetorheological fluid) testing device, the temperature of the device will increase, which will in turn affect the characteristics of the MRF. Exploring the temperature field characteristics of the MRF yield stress testing device is necessary to improve the accuracy of the device. In this study, first, the yield stress testing device is designed, and then its temperature field model, including enameled wire and assembly gap, is established. Second, simulation software is used to simulate the temperature field change. Finally, a test platform is developed to test the simulation results, especially for two factors, namely, thermal conductivity of the coil winding and assembly gap, which demonstrate considerable influence. Comprehensive thermal conductivity and assembly clearance are determined, and the optimum temperature field of the device for measuring yield stress is resulted.