توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Stability Analysis of Turning Process in the Presence of Tool Wear
نویسنده(ها): ، ،
اطلاعات انتشار: دومین کنفرانس بین المللی و هشتمین کنفرانس ملی مهندسی ساخت و تولید، سال
تعداد صفحات: ۸
Modeling of the Chatter vibration in machining processes is essential for suppression of this undesirable phenomenon. In this paper, orthogonal cutting process is modelled as a single degree of freedom dynamic system. A nonlinear delay differential equation is presented that models flank wear of the tool. Results of stability analysis for two distinct cases of a sharp tool and a worn tool are presented and compared. In addition, the effect of machining parameters such as tool wear length and cutting velocity is discussed in this analysis. It can be shown that in the case of a worn tool, the system is more stable.<\div>

۲Time Domain Simulation of Chatter in Reaming:Torsional–Axial and Bending Modes of Vibrations
نویسنده(ها): ،
اطلاعات انتشار: دومین کنفرانس بین المللی و هشتمین کنفرانس ملی مهندسی ساخت و تولید، سال
تعداد صفحات: ۹
A time domain approach is used in this paper to study the cutting conditions in reaming process that leads the system to regenerative chatter vibrations. Axial strain plus torsional– axial coupling and the first mode of bending of reamer are considered in the model. A model of cutting and thrust forces proportional to chip cross sectional area and process damping proportional to cutting speed is considered. Variation of time delay due to torsion of tool in response to torque changes is introduced to the model. A simulation using a numerical Euler integration technique has been used to find the time domain solution.<\div>

۳Dynamic Analysis of High Speed Spindles Based on a Simplified Model for Angular Contact Bearings
نویسنده(ها): ، ،
اطلاعات انتشار: دومین کنفرانس بین المللی و هشتمین کنفرانس ملی مهندسی ساخت و تولید، سال
تعداد صفحات: ۱۰
Accurate and realistic modeling of high speed spindles is essential for design of precision high speed machine tools. The bearings play an essential role in the dynamic performance of the spindles and their behavior is usually nonlinear. In this work, a five DOF simplified model for angular contact ball bearings is presented which takes into account the effects of high speed rotation on variation of the contact angles of the inner and the outer rings of the bearing. The model uses an average contact angle calculated at each rotational speed. It is shown that considering the changes in contact angles has a small effect on dynamic behavior of the bearing for typical range of spindle speeds currently available on most high speed machine tools. Therefore, the presented model can be safely used for modeling of the spindle bearings in such spindles with reasonable accuracy and reduced computational cost.<\div>

۴Some Numerical and Experimental Studies on the Indentation Forging of Thick– Walled Tubes
نویسنده(ها): ، ،
اطلاعات انتشار: اولین کنفرانس بین المللی و هفتمین کنفرانس ملی مهندسی ساخت و تولید، سال
تعداد صفحات: ۸
Indentation forging process is used for internal forming and sizing of thick–walled tubes designed to withstand high internal pressures. In this process, a mandrel with a diameter slightly larger than that of the tube is pressed inside the tube and in so doing, creates the internal profile. This paper presents an experimental and numerical study of this process. 2D Axisymmetric FEM analysis is used to investigate the effects of process parameters. Experiments are carried out to validate the numerical results.<\div>

۵Application of 3D FEM to Die Design in the Radial Forging Process
نویسنده(ها): ، ،
اطلاعات انتشار: اولین کنفرانس بین المللی و هفتمین کنفرانس ملی مهندسی ساخت و تولید، سال
تعداد صفحات: ۸
Radial forging is an open forging process used for reducing the diameters of shafts,tubes, stepped shafts and axels, as well as for creating internal profiles for tubes such as rifling the gun barrels. Most of previous studies conducted on the radial forging process have used axisymmetric models to investigate the effects of die shape on deformation. In order to design a hammer die for radial forging process, a full 3D model of the process is needed to consider the effects of die shape in the cross–section area on deformation. In this study, finite element method is used to model the radial forging process and to study the effects of die shape in the crosssection area on deformation.<\div>

۶Dynamic contact modeling of spindle –holder interface in milling
نویسنده(ها): ، ،
اطلاعات انتشار: هفدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۸
In this paper , a new contact model for tapered spindle holder interface is presented.<\div>

۷An ALE finite element procedure for finite deformantion of elasto –viscoplastic solids
نویسنده(ها): ، ،
اطلاعات انتشار: هفدهمین کنفرانس سالانه مهندسی مکانیک، سال
تعداد صفحات: ۷
In this paper , an analysis of large deformation of elastoviscoplastic materials is presented within the arbitrary lagrangian eulerian(ALE) finite element framework with a consistent integration procedure.<\div>
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