FEM analysis of manufacturing of a hollow product with an outer flange in a four-stage cold forming process

The paper presents the results of a FEM computer simulation of the cold forming process of a hollow sleeve forgings with an outer flange. Numerical simulations were carried out in DEFORM 2D / 3D. For the numerical calculations of the forming process the axisymmetric calculation module was used. As the test object, a tubular workpiece with an outer diameter of Ø50 mm and a wall thickness of 10 mm made of 42CrMo4 steel was used. The process of forming the rotary sleeve was conducted in four stages consisting of two technologies. The first stage of the research was the analysis and selection of parameters of the extrusion process, which was used for the first stage of forming. The processes of free extrusion and the use of a container were analysed. Furthermore different die angles and different wall thickness reductions were used. The products obtained in the extrusion process were upset in three conical blanks. The aim of the study was to analyse the numerical accuracy of the designed process of forming the hollow shaft with flange. The analysis of the results was based on the deformation intensity distribution maps, the Cockroft-Latham criterion distribution and the progress of the forming forces. On the basis of the conducted research, it was concluded that the presented process of forging a hollow product with a flange in four stages is possible to carry out correctly.

Formability Difference between TC4 Titanium Alloy Hollow Shaft and AISI 1045 Steel Hollow Shaft Formed by Cross Wedge Rolling with a Mandrel

Production of TC4 alloy hollow shaft formed by cross wedge rolling (CWR) can meet the needs of the lightweight structures in aviation field. Different from the steel, the formability of TC4 alloy is sensitive to deformation temperature. In this work, the formability difference of TC4 alloy hollow shaft and AISI 1045 steel hollow shaft formed by CWR with a mandrel was studied numerically and experimentally. The results show that the influence of temperature on TC4 alloy flow stress is larger than that of 1045 steel, and the peak stress of TC4 alloy at 900 °C is close to that of 1045 steel at 1050 °C. For the hollow shafts of two materials, the ellipticity increases with increasing the inner hole diameter. For the same size of thin-walled billets, the forming quality of TC4 alloy at 900 °C is better than that of 1045 steel at 1050 °C. The CWR temperature range of TC4 alloy is narrower than 1045 steel. The increase of the initial deformation temperature can significantly increase the ellipticity of TC4 alloy and the appropriate forming temperature range of CWR TC4 alloy hollow shaft should be lower than 950 °C. Moreover, the rolling force and torque of TC4 alloy hollow shaft are smaller than that of 1045 steel when CWR hollow billet with the same dimensions.

A New Method of Manufacturing Hollow Shafts via Flexible Skew Rolling

The existing rolling process of large and long axle parts, such as the cross wedge rolling (CWR) process, requires special molds and larger equipment. Flexible skew rolling (FSR) hollow shafts with mandrel is a near net-shape rolling technology which can achieve the diversified production of rolled parts without special molds. It has significant advantages such as small equipment tonnage, small die size, low rolling load, simple process adjustment, and especially suitable for multi-variety and small-batch production. This paper proposes hollow train shafts formed by FSR with mandrel. Reasonable parameters were selected for experiments, and the forming process was calculated by finite element (FE) software. The experimental results are consistent with the simulation results, indicating that the FE model is reliable. The rolling force and rolling torque are analyzed by simulation. Finally, the microstructure of different positions of the rolled-piece is analyzed, and the microstructure of the rolled part is refined. It is provide a feasible scheme for the rolling of large hollow shaft parts.

Design and Fatigue Optimization of Drive Shaft

This work aims towards the design and optimization of the drive shaft as there is increasing demand for weight reduction in an automobile vehicle. The drive shaft is basically a torque transmitting element which transmit the torque from the differential gearbox to the respective wheels. In general, the drive shafts are subjected to fluctuating loads as the torque requirement changes according to the road conditions. Due to this, the drive shaft should be designed considering fatigue failure. The Maruti Suzuki Ertiga model is chosen for design and optimization of the drive shaft. For the fatigue life predicting of the drive shaft, the S-N curve approach is used. Furthermore, the inner diameter of the shaft is varied to obtain the optimized diameter of a hollow shaft which can withstand these fluctuating loads without failure. Along with fatigue life prediction, the natural frequency of the hollow shaft is also calculated. Furthermore, the parametric analysis is carried out of fatigue FOS, Von mises stress, weight and natural frequency of the shaft by varying the diameter ratio of the hollow shaft, and the nature of variation of these parameters are plotted in their respective graphs. The design is validated by performing FEA analysis for each case of a hollow shaft using Ansys software. Finally, from the FEA analysis we conclude that the optimized dimensions of the hollow drive shaft are safe.

Investigations on digitalization for sustainable machine tools and forming technologies

Progress in applied research for sustainable machine tools and forming technologies bases upon industrial and environmental requirements for resource efficiency. Relevant technical trends base upon impact studies and applied research projects on the lifecycle resource consumption for manufacturing processes and systems. This paper gives an overview about a unified methodological approach of the evaluation of resource efficiency of machine tools. It answers the scientific question on sustainability: which technological parameters and machine tool characteristics lead to their lowest resource consumption/losses and part manufacturing costs. Therefore, the method allows to consider them as an energy-information model, in which the transformation of any forms and types of energy, material, and information takes place. It is shown that innovative hollow shaft forming technologies become sustainable alternatives to cutting technologies. A smart factory uses digitalization, manufacturing data management, and self-learning methods for resource efficiency. Sustainable production requires robust and error-free machining processes. Therefore, a collision prevention system protects machining centers and work pieces from collisions in real time will be presented. The gathered information about the product and its properties as well as manufacturing data builds a digital twin and enables a prediction of the resource consumption in smart factories.

3-D analytical model for bending stiffness of thick-walled composite hollow shaft

In this paper, the Layer-wise theory was improve based on the alternate characteristics of layer angle of composite hollow shaft. The ±φi laminate was considered as the minimum mechanical analysis element, which can effectively simplify the stress coupling in mechanical analytical method. On this foundation, a 3-D analytical method of bending stiffness < EI> for thick-walled composite hollow shaft was derived. The CFRP hollow shaft specimens made of same dimensions but different laminate were used for bending test. Then, the bending stiffness calculated by theory of beams, 2-D analytical method, 3-D analytical model and experiment were compared. All the results show that the 3-D analytical model predicts the bending stiffness of thick-walled composite hollow shaft more precisely than the theory of beams and analytical method, and agree well with experimental results. And the 3-D analytical model can reflect the influence of stacking sequence on the bending stiffness of the composite hollow shaft.