A Mathematical Model to Describe the Inner Contour of Moineau Stators

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Ekrem Oezkaya ◽  
Moritz Fuss ◽  
Dirk Biermann
Keyword(s):  
Mathematical Model ◽  
Machining Process ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Hole Drilling Method ◽  
Current State ◽  
Drilling Method ◽  
Large Length

Abstract Bore holes with a large length to diameter ratio of up to l/d = 100 are typically produced using the single-tube deep hole drilling method also named BTA (Boring and Trepanning Association) deep hole drilling method. However, there are various technical applications requiring deep, complex, epitrochoid-similar and helical inner contours, such as stators used in Moineau motors and pumps. According to the current state of the art, epitrochoid-similar contours for small diameters with large drilling depths can only be produced using a special machining process which is referred to a chamber-boring process. In this paper, a developed mathematical model will be presented that describes the epitrochoid-similar contour exactly. This allows the determination of the position-dependent speed and acceleration of the tool, which are necessary for designing the joints and components of the tool system. In addition, this mathematical model can be used for a subsequent Laplace-transformation, so that could be used for a further optimization of the process dynamic in the future.

Simulation and Measurement of Residual Stresses in a Stainless Steel Ring Welded Circular Disc

2012 ◽  
Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Mike Smith ◽  
David Smith
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Circular Disc ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method

Residual stresses were predicted and measured in a circular disc containing a partial ring weld. This study first created an axisymmetric finite element model so that the process of introducing the ring weld was simulated using thermal and mechanical modelling. The resulting residual stresses were then mapped onto a 3D model which included the necessary mesh and boundary conditions to simulate the process of residual stress measurement using the deep hole drilling method. Then an experimental programme of residual stress measurement using the deep hole drilling method and the neutron diffraction technique was conducted on the welded circular disc. The results from the deep hole drilling measurements matched well with the neutron diffraction results on the original stress field in the ring weld. While comparison between measurements and predicted residual stresses show that predicted hoop stresses are slightly higher than measured, there is in general a fair comparison between measured and predicted residual stress.

scholarly journals Temperature monitoring in the subsurface during single lip deep hole drilling

2020 ◽  
Vol 87 (12) ◽  
pp. 757-767
Author(s):  
Robert Wegert ◽  
Vinzenz Guski ◽  
Hans-Christian Möhring ◽  
Siegfried Schmauder
Keyword(s):  
Cutting Parameters ◽  
Drill Hole ◽  
Machining Process ◽  
Hole Drilling ◽  
Drilling Process ◽  
Deep Hole ◽  
Machining Processes ◽  
Deep Hole Drilling ◽  
Feed Force ◽  
Cutting Zone

AbstractThe surface quality and the subsurface properties such as hardness, residual stresses and grain size of a drill hole are dependent on the cutting parameters of the single lip deep hole drilling process and therefore on the thermomechanical as-is state in the cutting zone and in the contact zone between the guide pads and the drill hole surface. In this contribution, the main objectives are the in-process measurement of the thermal as-is state in the subsurface of a drilling hole by means of thermocouples as well as the feed force and drilling torque evaluation. FE simulation results to verify the investigations and to predict the thermomechanical conditions in the cutting zone are presented as well. The work is part of an interdisciplinary research project in the framework of the priority program “Surface Conditioning in Machining Processes” (SPP 2086) of the German Research Foundation (DFG).This contribution provides an overview of the effects of cutting parameters, cooling lubrication and including wear on the thermal conditions in the subsurface and mechanical loads during this machining process. At first, a test set up for the in-process temperature measurement will be presented with the execution as well as the analysis of the resulting temperature, feed force and drilling torque during drilling a 42CrMo4 steel. Furthermore, the results of process simulations and the validation of this applied FE approach with measured quantities are presented.

Residual Stress Analysis in Containers for Transport of Radioactive Materials

2015 ◽  
Vol 732 ◽  
pp. 28-31 ◽  
Author(s):  
František Trebuňa ◽  
František Šimčák ◽  
Miroslav Pástor ◽  
Patrik Šarga
Keyword(s):  
Residual Stresses ◽  
Experimental Methods ◽  
Hole Drilling ◽  
Thermal Processes ◽  
Safe Operation ◽  
Radioactive Materials ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Residual Stress Analysis

During verification of safe operation of containers for radioactive waste is possible to use analytical, numerical and experimental methods of mechanics. Determination of residual stresses was one part of analysis. The residual stresses in container body can be induced during their production, overloading during operation, radiation or by thermal processes. In the paper are presented results from analysis of residual stresses in containers by using strain-gage hole-drilling method.

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