Part Of Complex Mechanism Research Articles

Generation of consistent skin model shape based on FEA method

Controlling product geometric quality is an important issue, because real parts deviate from their nominal value (e.g., in form, orientation, and position error of features, size of part, etc.). To analyze the influence of these deviations on final product, one solution is to consider the nonnominal Skin Model Shape to simulate assembly, manufacturing, or metrology. The modeling of nonnominal parts is still in its initial phases. First, methods of generating a single feature with deviations are reviewed and classified. With the combination of the single nonideal features to obtain the complete nonideal model of the part, geometrical issues appear, such as gaps and self-intersections. These can be influenced by acute and obtuse angles and the ratio between mesh size and deviation value. From an analysis of these issues, two deviation combination methods are proposed to preserve the manufacturing deviation of features and consistency of the model. These methods are qualified as local and global methods. The local method is based on the iterative calculation of mesh regularization. The global method is based on finite element analysis, with manufacturing deviations added to the nominal model by the penalty function approach. The effectiveness and efficiency of both kinds of method are compared on a trial geometry. The global method is preferred as it needs no iterative calculation, no stop criteria and gives better results. Finally, the proposed method is validated on a more complex mechanical part: a cutter body.

Heterogeneous model integration of complex mechanical parts based on semantic feature fusion

Due to the rapid development of computer, sensor, and automatic control technologies, the amount of data generated during product design and manufacturing is increasing significantly. The product data bank is large, complex, heterogeneous, and often fast-changing; it is difficult to integrate heterogeneous models using the conventional method. Therefore, a semantic feature fusion-based heterogeneous model integration method is proposed. First, the error in the geometric dimensions and position are extracted using model registration. Second, the basic geometric feature is obtained using slippage analysis. Third, the extracted data, such as the basic geometric feature and the error in the geometric dimensions and position, are fused into the design model using the level set method. Finally, the marching cubes method is introduced to reconstruct the surface of the fused model. The empirical results demonstrate that the proposed algorithm can integrate all types of semantic features and geometric features into a basic product model effectively and efficiently.

Innovational Mechanism of Implementation of Cluster Initiatives in Business

The authors view the problems of developing countries and create innovational organizational and managerial mechanism of clustering, aimed at solving these problems and adapted for provision of sustainable regional development in view of clustering. As a result of the research, the authors come to the conclusion that realization of potential of clustering in the increase of competitiveness of regional economy can be achieved by means of formation of complex mechanism of management of regional socio-economic development. That’s why, in order to receive maximum profit from clustering, innovational organizational & managerial mechanism of realization of cluster initiatives in business should be based on formation of regional innovational clusters as a part of complex mechanism of management of regional development. The mechanism that is offered in the article aims at solving the problems of developing countries in the sphere of clustering by means of coordination of actions of regional authorities and members of cluster entities. Cooperation and interaction of members of cluster entity and regional authorities are oriented at the increase of efficiency of cluster functioning and achievement of goals of regional development in economic, social, and ecological spheres.

Improved Surface Quality by the Process of Vibratory Grinding

The main purpose of this work is the energy saving by reducing friction and minimizing wear to avoid losses by raising the properties of nanomaterials on the surface layer. Therefore, we develop approaches for studying the tribological behavior phenomena concerning materials on surfaces of the layers to define the mechanical and tribological properties of materials to improve the surface layer materials of the treated parts. It was used for the vibratory grinding method of chemical mechanical processing surface using the technology of low-frequency vibration in the treatment of metal parts in the presence of chemical additives, which have a great influence on the improvement of mechanical and geometrical parameters (roughness, fatigue resistance, corrosion resistance, micro and macro hardness, structure) of mechanical parts. This method of vibratory grinding has great advantages such as the treatment of complex mechanical parts, the ability to process parts of different types and shapes at the same time. It is also known to be an environmentally friendly process. Thus this work consisted of a surface treatment by vibratory grinding of samples of different materials.

Adaptive neuro-fuzzy PID controller for nonlinear drive system

Purpose – Various control structures and approaches are in use nowadays. Development of new ideas allows to obtain better quality in control of different industrial processes and hence better quality of products. As it may seem that everything in the classical systems has already been discovered, more and more research centres are tending to incorporate fuzzy or neural control systems. The purpose of this paper is to present an application of the adaptive neuro-fuzzy PID speed controller for a DC drive system with a complex nonlinear mechanical part. Design/methodology/approach – The model of the driven object including such elements as nonlinear shaft with backlash and friction has been modelled using Matlab-Simulink software. Afterwards experimental verification has been made using a dSPACE control card and experimental system with two DC motors connected with an elastic shaft. Findings – The presented study shown that the adaptive controller is able to damp the torsional vibration effectively even for ...

Investigation of Sensitivity Effect Based on Mass and Stiffness Modification in Automobile Crankshaft

A modeling through sensitivity analysis is one of the promising methods to investigate the dynamic characteristics of complex mechanical parts. This study aimed to investigate the effect of sensitivity based on mass and stiffness modification in automobile crankshaft as a function of natural frequency. Verification for the crankshaft model that is used in the experiment and simulation was done and both results showed good agreement and small errors percentage. The modification was also done by reducing the different percentage of crankshaft’s mass and stiffness. Partial differential analysis was used in the sensitivity analysis in order to figure out the natural frequency after every set of modification. According to the results, we also found that there were changes of sensitivity value by changes in mass value but the stiffness value remains unchanged. However, there is no significant effect of stiffness reduction on vibration was found in this research.

Optimised design for magnetorheological brake using DOE methods

Nowadays, the automobile systems like suspension, transmission, braking and clutch systems are controlled through the wire concept. To overcome the drawbacks of the existing conventional hydraulic braking system (CHB), magnetorheological brake (MRB) is introduced in this project. CHB require complex mechanical parts to dissipate energy. A magnetorheological fluid (MRF) brake is more efficient than conventional braking system in terms of weight reduction and response time. The research work is concerned with the development of a new braking system which employs MRF as working medium. MRB design proposed in earlier studies is to be further improved according to additional practical design criteria and constraints and more in-depth electromagnetic finite element analysis. The design procedure comprises the selection of materials for MRB, creating an analytical model for finding the braking torque produced by the MRB and finite element analysis of the MRB.

Design and Analysis of Magneto-Rheological Fluid Brake (MRB)

Magneto-rheological fluids are smart fluids displaying flow properties that can be adjusted by the introduction of magnetic fields. Conventional brakes require complex mechanical parts to dissipate energy, they are having more weight, produce less braking torque and the time of response is about 300-500 milliseconds and hence brake distance is high. A Magneto-rheological fluid brake is more efficient than conventional braking system in terms of the weight reduction, and response time. In this paper an improved MRB design is made, taking into account the temperature effects and more accurate description of the material properties as well. The proposed work is concerned with the development of a new Brake-by-wire system which employs MRF as working medium. The design procedure comprises the selection of materials for MRB, creating an analytical model for finding the braking torque produced by the MRB and Finite Element Analysis of the MRB. Finite element models are built to provide a means to analyze the performance of the magneto-rheological brake system. The formulation of these models (including the definition of the geometry, material properties, boundary conditions and meshing process, as well as necessary assumptions) are described. The results obtained with the finite element models are presented and analyzed using SolidWorks 2013® and COMSOL Multiphysics 4.3b®.

Preparation of MR Fluid and Modeling of Magneto Rheological Fluid Brake (MRB)

Magneto-rheological fluids are smart fluids displaying flow properties that can be adjusted by the introduction of magnetic fields. Conventional brakes require complex mechanical parts to dissipate energy, they are having more weight, produce less braking torque and the time of response is about 300-500 milliseconds and hence brake distance is high. A Magneto-rheological fluid brake is efficient than conventional braking system in terms of the weight reduction, and response time. In this paper MR fluid is prepard and an improved MRB design is made, taking into account the temperature effects and more accurate description of the material properties as well. The proposed work is concerned with the development of a new Brake-by-wire system which employs MRF as working medium. The design procedure comprises the selection of materials for MRB, creating an analytical model for finding the braking torque produced by the MRB and Finite Element Analysis of the MRB.

Loss of heterozygosity in ING3 and ING5 genes in breast cancer

The tumor suppressor genes (TSGs) ING3 and ING5, members of the inhibitor of growth gene family, are effective in inhibition of cell growth and induction of apoptosis. However, in many cancer types, one of the alleles of a TSG is lost through carcinogenesis, while the remaining allele is usually inactivated through a process called loss of heterozygosity (LOH). Previous studies in head and neck cancer revealed that allelic loss and reduced expression is a common pattern of ING gene family members. Fifty paraffin-embedded breast cancer tissues were analyzed by polymerase chain reaction and denatured-polyacrylamide gel electrophoresis for LOH status. The allelic deletion frequency of ING3 and ING5 were detected as 14% and 17% in breast cancer patients, respectively. No significant relationship was detected between ING3 LOH status and clinicopathological variables. Our data also suggest that both ING3 and ING5 LOH statuses have no significant effect in overall survival and disease-free survival of breast cancer patients. These results provide a rational explanation and relative contribution for the complexity of tumor formation, whereby allelic loss of ING3 and ING5 genes is not a major factor for breast cancer but is rather a part of a larger complex mechanism.

Monitoring of the microstructure and mechanical properties of the magnesium alloy used for steering wheel manufacturing

The article presents the microstructure and mechanical properties of magnesium steering wheels. These steering wheels are manufactured by high pressure die casting. High-pressure die casting (HPDC) is a very good process for making complex mechanical parts out of light metals like magnesium and aluminium alloys. However, in recent times, another light metal has come to the forefront in the quest for lighter vehicles and improved fuel economy. The most commonly used magnesium alloy for die casting automotive components is of the Mg-Al-Mn type. MgAl5Mn is a good purity magnesium alloy with good corrosion resistance, very good mechanical properties and good castability. Mg-Al-Mn based alloys such as MgAl5Mn and MgAl6Mn have better elongation and impact strength than MgAl9Zn, and they are mainly used for auto safety systems like wheel rims and steering wheels. Alloy MgAl5Mn is an alloy with outstanding ductility and energy absorbing properties combined with good strength. This alloy, in the solid state, contains a solid solution α and the intermediate phase Mg17 Al12.

Fundamental study on improvement of piezoelectricity of poly(ι-lactic acid) and its application to film actuators

We designed a new film actuator, whose driving force is generated by a surface wave, which induces rotational motion. Its performance is similar to that of a rotation motor even though the new film actuator has no complex mechanical parts. To realize the film actuator, we used a poly(l-lactic acid) (PLLA) film with improved piezoelectricity. First, we theoretically investigated the necessary conditions for a surface wave to be generated on the end face of a PLLA film by the fusion of its shear piezoelectricity and resonance, and then experimentally realized this. Using the actuator made using the PLLA film, we demonstrated that the clockwise and counterclockwise rotation of an object placed on the end face of the PLLA film actuator could be freely controlled by changing the frequency of the ac voltage applied to the actuator.

Fundamental Study of Application of Piezoelectric Chiral Polymer to Actuator

To realize a new piezoelectric chiral polymer actuator, we studied the motion induced by the shear piezoelectricity of a poly(L-lactic acid) (PLLA) film under the application of an ac voltage. First, PLLA was subjected to a supercritical CO2 treatment to change its high-order structure, resulting in an improvement in its piezoelectricity. Then, we designed a PLLA film roll transducer, which consisted of a piece of the treated PLLA film rolled into a long thin roll. To demonstrate the transducer, we placed it vertically on a fixed stand. A plastic hemispherical container was placed on the upper end face of the transducer. It was found that the container rotated smoothly in the counterclockwise direction when an ac voltage was applied. We emphasize that no special complex mechanical parts were used in this study.

Numerical Analysis of a New Location for the Working Volume Inside a Reverberation Chamber

This paper analyzes the performance of a reverberation chamber when the working volume (WV) is positioned inside the stirrer rotating volume. More precisely, considering a very large stirrer, its inner surface and axis are removed to gain a large space to be used as WV. The design of this new WV position and stirrer shape is done using our finite-difference time domain code, previously optimized for reverberation chamber simulations and tested with experimental results. The proposed setup increases the WV and improves the reverberation chamber behavior with respect to a traditional setup. Moreover, it needs just one motor to control the stirrer, and it does not require more complex mechanical part.

Differential response of Drosophila cell lines to extracellular adenosine

Adenosine (Ado) is a crucial metabolite that affects a wide range of physiological processes. Key proteins regulating Ado signaling, transport and metabolism are conserved among vertebrates and invertebrates. It is well known that Ado influences proliferation of several vertebrate and invertebrate cells. Here we show that Ado negatively influences viability, changes morphology and mitochondrial polarity of the Drosophila imaginal disc cell line (Cl.8+) via a mechanism exclusively dependent on cellular Ado uptake. High transport of Ado is followed by phosphorylation and ATP production as a part of Ado salvation, which at higher concentrations may interfere with cellular homeostasis. In contrast, hematopoietic cell line Mbn2, which grows well in high Ado concentration, preferentially uses adenosine deaminase as a part of the purine catabolic pathway. Our results show that different types of Drosophila cell lines use different pathways for Ado conversion and suggest that such differences may be an important part of complex mechanisms maintaining energy homeostasis in the body.

Local scale-based 3D model retrieval for design reuse

3D model retrieval plays an important role in product design reuse. We present a local scale-based model retrieval methodology for 3D mechanical parts library. On the grounds that most of the mechanical parts have visible main planes, we firstly propose a novel approach, i.e., the plane comparison-based pose normalization. This approach was employed complementally with principal component analysis (PCA for short) on the normals of the model's face to perform rotation invariance. After pose normalization, the model is scaled locally along a certain axis so that the size of its local features can be adjusted reasonably. In this way, the feature vectors of the scaled model can represent all the local features. The feature vectors of the deformed model are extracted by the real spherical harmonics. Finally, the feature vectors and the scale factors are used in an experiment for similarity comparison. Experimental results showed that the proposed method outperformed five other methods on the National Design Repository dataset and our own complex mechanical parts dataset.

Peening on Mechanical Parts of Complex Shape by High-Speed Submerged Water-Jet Accompanied by Uniformly Large Bubble-Cloud (1st Report, The Cloud-Effect-Confirmation for Parts of Complex Shape)

Recently, the high-speed submerged water-jet peening using the high impact pressures being accompanied by the bubble collapse is attracting attention. In this study, therefore, in order to improve such a peening effect and to make rapid progress of the applicable range, we take up a typical water-jet accompanied by uniformly large bubble-cloud, the time dependent change of residual stress is systematically measured on the gear surface by means of the X-ray diffraction method for a complex mechanical part of complicated shape (single helical gear of SCr420H3V2L2 carbon steel), and the definite peening effectiveness has been verified. We show on the surface that the residual tensile stress can be effectively improved into the residual compressive stress. It is also confirmed that uniform peening effect well works even for such very complex parts.

Information technologies applied to the manufacturing of complex mechanical parts

The aim of the present paper is to report the use of information technologies to control and assure the quality of complex mechanical parts, in this case crankshafts. Three different automated cells are used for inspection purposes using Non Destructive Techniques (NDT): Automated Visual Inspection (AVI), a surface Roughness Measurement System (RMS) and a Dimensional Control System (DCS). Distributed control architecture allows integral quality assessment of the production process of valuable machined components. A suitable software subsystem has been developed for this architecture: a Quality Assessment Subsystem (QUAL), a Tracking Subsystem (TS) and an intelligent production Process Assessment Subsystem (PAS). A prototype has been successfully installed and is under evaluation in a production line belonging to Renault Industrial Vehicles (Spain).

Pharmacomechanical coupling: the role of calcium, G-proteins, kinases and phosphatases.

The concept of pharmacomechanical coupling, introduced 30 years ago to account for physiological mechanisms that can regulate contraction of smooth muscle independently of the membrane potential, has since been transformed from a definition into what we now recognize as a complex of well-defined, molecular mechanisms. The release of Ca2+ from the SR by a chemical messenger, InsP3, is well known to be initiated not by depolarization, but by agonist-receptor interaction. Furthermore, this G-protein-coupled phosphatidylinositol cascade, one of many processes covered by the umbrella of pharmacomechanical coupling, is part of complex and general signal transduction mechanisms also operating in many non-muscle cells of diverse organisms. It is also clear that, although the major contractile regulatory mechanism of smooth muscle, phosphorylation/dephosphorylation of MLC20, is [Ca2+]-dependent, the activity of both the kinase and the phosphatase can also be modulated independently of [Ca2+]i. Sensitization to Ca2+ is attributed to inhibition of SMPP-1M, a process most likely dominated by activation of the monomeric GTP-binding protein RhoA that, in turn, activates Rho-kinase that phosphorylates the regulatory subunit of SMPP-1M and inhibits its myosin phosphatase activity. It is likely that the tonic phase of contraction activated by a variety of excitatory agonists is, at least in part, mediated by this Ca(2+)-sensitizing mechanism. Desensitization to Ca2+ can occur either through inhibitory phosphorylation of MLCK by other kinases or autophosphorylation and by activation of SMPP-1M by cyclic nucleotide-activated kinases, probably involving phosphorylation of a phosphatase activator. Based on our current understanding of the complexity of the many cross-talking signal transduction mechanisms that operate in cells, it is likely that, in the future, our current concepts will be refined, additional mechanisms of pharmacomechanical coupling will be recognized, and those contributing to the pathologenesis diseases, such as hypertension and asthma, will be identified.

Virtual reality interfaces for feature-based computer-aided design systems

A computer-aided design ( cad) system with a virtual reality (VR) interface simplifies the design of complex mechanical parts. To add a design feature (e.g., a hole, slot, or protrusion), the designer can navigate in the part to the appropriate face of the part where he/she wishes to attach the feature, and sketch directly on that face. Besides convenience, this method of feature specification implicitly enforces feature accessibility constraints, and also provides hints to the process-planner regarding the order in which the features may be manufactured. We detail the design of a VR-based prototype cad system. The system maintains the knowledge of part cavities and their adjacencies, and a triangulated boundary-representation of an approximating polyhedron. We present incremental provably correct algorithms for updating this representation as the user edits the part. We also show how this representation supports real-time displays, navigation, and collision detection. The user-interface of the cad system relies on these capabilities to provide the above-mentioned advantages.