scholarly journals Facile Fabrication of Highly Perforated Hollow Metallic Cylinder with Changeable Micro-Orifices by Electroforming-Extrusion Molding Hybrid Process

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 70
Author(s):  
Junzhong Zhang ◽  
Pingmei Ming ◽  
Xinmin Zhang ◽  
Ge Qin ◽  
Liang Yan ◽  
...  
Keyword(s):  
Hollow Cylinder ◽  
Hybrid Process ◽  
Hybrid Technique ◽  
Polymer Extrusion ◽  
Promising Alternative ◽  
Moulding Process ◽  
Electroforming Process ◽  
Metallic Cylinder ◽  
Thin Walled ◽  
The Given

A seamless thin-walled hollow metallic cylinder with array of micro-perforations is one of the key components for some products. Normally, these micro-perforations are formed by removing material from the given metallic hollow cylinder (pipe or tube) one by one or row by row. To efficiently and flexibly manufacture such a highly perforated hollow cylinder, this paper proposed a hybrid technique combining extrusion moulding process and electroforming process. In the hybrid technique, the extrusion moulding process was used to create polymer extrusion patterns on the outside surface of the given stainless steel (SS) pipe, and then the electroforming process was carried out using the SS pipe as the mandrel. The formation of the polymer extrusion patterns was simulated and extruding molding experiments were carried out to examine the feasibility of the various mandrels. Electroforming experiments were implemented to verify the achievement of the seamless perforated thin-walled hollow cylinder. It was found that five different types of polymer extrusion pattern were able to be obtained on the same extruding pipe just by adjusting some extruding conditions and parameters, and correspondingly four types of perforated hollow cylinder with different tapered orifices are produced after the electroforming process. The obtainable perforations are: perforation with double conic-orifices, perforation with hemispheric orifice and conic orifice, unidirectionally tapered perforation, and straight-walled perforation. The geometric profile of the extrusion patterns is highly dependent on the processing conditions and parameters. The proposed hybrid process represents a promising alternative process to fabricate seamless thin-walled perforated hollow metallic cylinder efficiently, flexibly, and with low cost.

Post-buckling inelastic analysis of thin-walled metal members using the Generalised Beam Theory

2019 ◽  
Author(s):  
Miguel Abambres ◽  
Dinar Camotim ◽  
Miguel Abambres
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Beam Theory ◽  
Flow Theory ◽  
Promising Alternative ◽  
Inelastic Analysis ◽  
Post Buckling ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Generalised Beam Theory

A 2nd order inelastic Generalised Beam Theory (GBT) formulation based on the J2 flow theory is proposed, being a promising alternative to the shell finite element method. Its application is illustrated for an I-section beam and a lipped-C column. GBT results were validated against ABAQUS, namely concerning equilibrium paths, deformed configurations, and displacement profiles. It was concluded that the GBT modal nature allows (i) precise results with only 22% of the number of dof required in ABAQUS, as well as (ii) the understanding (by means of modal participation diagrams) of the behavioral mechanics in any elastoplastic stage of member deformation .

scholarly journals Numerical Simulation on Moulded Thin-Walled Parts via Injection Moulding Process

2014 ◽  
Vol 575 ◽  
pp. 73-77
Author(s):  
M.D. Azaman ◽  
S.M. Sapuan ◽  
Shamsuddin Sulaiman ◽  
E.S. Zainudin ◽  
Abdan Khalina
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Residual Stresses ◽  
Current Trend ◽  
Light Weight ◽  
Moulding Process ◽  
Injection Moulding Process ◽  
Low Shear Stress ◽  
Thin Walled ◽  
Low Shear

The current trend in the industry is to produce thin, light weight, and environmental products. In this project, flat or shallow thin-walled parts were designed and moulded lignocellulosic polymer composites (PP + 50 wt% wood) to visualize the processability via moulding simulation. This studied focused on the filling, shear stress at wall, and in-cavity residual stresses behaviors. The shallow thin-walled part is preferable in moulding PP + 50 wt% wood due to economically in processing, low shear stress distribution and low residual stresses than the flat thin-walled part.

Analysis of Cutting Technologies for Lightweight Frame Components

2006 ◽  
Vol 10 ◽  
pp. 121-132 ◽  
Author(s):  
Klaus Weinert ◽  
Sven Grünert ◽  
Michael Kersting
Keyword(s):  
Finite Element ◽  
Metal Cutting ◽  
Thermal Stresses ◽  
Machining Process ◽  
Frame Structure ◽  
Experimental Investigations ◽  
Promising Alternative ◽  
Thin Walled ◽  
Process Strategy ◽  
Conventional Drilling

Most technical components applied in industrial practice are subjected to metal cutting operations during their production process. However, this leads to undesirable thermal and mechanical loads affecting the machined workpiece, which can result in an impairment of its serviceability. Due to their small wall thickness lightweight hollow profiles are highly susceptible to the inevitable machining loads and thermal stresses during drilling processes. For the virtual optimization of the machining process and in order to ensure a suitable process strategy, a finite element simulation of cutting operations for thin-walled light metal profiles is conducted. Due to the flexibility within creating drill holes of different diameters without tool changes circular milling represents a promising alternative to the application of conventional drilling tools for variable process strategies to handle batch sizes down to one piece efficiently. Hence, this article gives an insight into the investigations regarding the modeling concepts of the mechanical and thermal loads induced into the thin-walled lightweight frame structure during the circular milling process. Furthermore, process reliability aspects as well as the correlation of the calculated and the measured results will be discussed on the basis of experimental investigations. Finally, this article compares Finite Element Analysis aspects of circular milling processes with conventional drilling processes.

Instability of a Hollow Elastic Cylinder Under Tension, Torsion, and Inflation

2007 ◽  
Vol 75 (1) ◽  
Author(s):  
Leonid M. Zubov ◽  
Denis N. Sheidakov
Keyword(s):  
Hollow Cylinder ◽  
Stability Region ◽  
Three Dimensional ◽  
Elastic Stability ◽  
Elastic Cylinder ◽  
Elastic Instability ◽  
Incompressible Medium ◽  
Compressive Loads ◽  
Thin Walled ◽  
External Loads

Background. Many papers on the elastic stability of both thin-walled and massive (three-dimensional) bodies regard the bifurcation of equilibrium in the case of compressive loads. Although, the elastic instability may also occur under tensile stresses. Method of Approach. In the present paper on the basis of three-dimensional equations of the nonlinear elasticity the instability of a stretched infinite hollow cylinder under torsion and inflation is investigated. The bifurcational method of stability analysis is used. Results. The critical surfaces and stability region in the space of loading parameters are defined for a Biderman material and special model of incompressible medium, which possess essential material nonlinearity. The influence of a wall thickness on the instability of a hollow cylinder is analyzed. Conclusions. Based on the obtained results, a simple and efficient practical criterion of stability under tension is formulated. This criterion can be represented in the form of the Drucker postulate, given in terms of external loads.

scholarly journals Numerical Simulation Analysis of Unfilled and Filled Reinforced Polypropylene on Thin-Walled Parts Formed Using the Injection-Moulding Process

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
M. D. Azaman ◽  
S. M. Sapuan ◽  
S. Sulaiman ◽  
E. S. Zainudin ◽  
A. Khalina
Keyword(s):  
Glass Fibre ◽  
Injection Moulding ◽  
Simulation Analysis ◽  
Fibre Composite ◽  
Wood Composite ◽  
Moulding Process ◽  
Injection Moulding Process ◽  
Part Surface ◽  
Thin Walled ◽  
Glass Fibre Composite

Thin-walled moulding technology has attracted increasing attention, particularly in electronic packing applications. The injection moulding of shallow, thin-walled parts with a thickness of 0.7 mm was performed using three types of materials from polypropylene, PP (PP, PP + 50 wt% wood composite, and PP + 10 wt% glass fibre composite). The highest deflection resulting from PP + 50 wt% wood does not occur in the critical area of the thin-walled part compared with PP + 10 wt% glass fibre. In addition, the results revealed that the warpage at the midpoint of the part surface injected using PP + 50 wt% wood is 0.04 mm lower than the value of 0.08 mm obtained when injected using PP + 10 wt% glass fibre. The warpage was hypothesised to result from the residual stress caused by nonuniform volumetric shrinkages formed during the solidification phase.

scholarly journals Regression Test Suite Reduction using an Hybrid Technique Based on BCO And Genetic Algorithm

2013 ◽  
pp. 26-33
Author(s):  
Bharti Suri ◽  
Isha Mangal ◽  
Varun Srivastava
Keyword(s):  
Optimization Problems ◽  
Minimum Time ◽  
Test Suite ◽  
Test Case ◽  
Hybrid Technique ◽  
Bee Colony ◽  
Bee Colony Optimization ◽  
Test Suite Reduction ◽  
The Given ◽  
Swarm Intelligence Algorithm

Regression testing is a maintenance activity that is performed to ensure the validity of modified software. The activity takes a lot of time to run the entire test suite and is very expensive. Thus it becomes a necessity to choose the minimum set of test cases with the ability to cover all the faults in minimum time. The paper presents a new test case reduction hybrid technique based on Genetic algorithms(GA) and bee colony optimization (BCO) .GA is an evolutionary algorithms (EA), which generate solutions to optimization problems using techniques inspired by natural evolution, such as inheritance, mutation, selection, and crossover. BCO is a swarm intelligence algorithm. The proposed approach adopts the behavior of bees to solve the given problem. It proves to be optimistic approach which provides optimum results in minimum time.

scholarly journals Novel Analysis of Fuzzy Physical Models by Generalized Fractional Fuzzy Operators

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
Mohammed Kbiri Alaoui ◽  
F. M. Alharbi ◽  
Shamsullah Zaland
Keyword(s):  
Initial Conditions ◽  
Dynamical Behavior ◽  
Physical Models ◽  
Hybrid Technique ◽  
Gas Dynamics Equations ◽  
Transform Method ◽  
Unknown Quantity ◽  
Fuzzy Solution ◽  
Generalized Hukuhara Differentiability ◽  
The Given

The present article correlates with a fuzzy hybrid technique combined with an iterative transformation technique identified as the fuzzy new iterative transform method. With the help of Atangana-Baleanu under generalized Hukuhara differentiability, we demonstrate the consistency of this method by achieving fuzzy fractional gas dynamics equations with fuzzy initial conditions. The achieved series solution was determined and contacted the estimated value of the suggested equation. To confirm our technique, three problems have been presented, and the results were estimated in fuzzy type. The lower and upper portions of the fuzzy solution in all three examples were simulated using two distinct fractional orders between 0 and 1. Because the exponential function is present, the fractional operator is nonsingular and global. It provides all forms of fuzzy solutions occurring between 0 and 1 at any fractional-order because it globalizes the dynamical behavior of the given equation. Because the fuzzy number provides the solution in fuzzy form, with upper and lower branches, fuzziness is also incorporated in the unknown quantity. It is essential to mention that the projected methodology to fuzziness is to confirm the superiority and efficiency of constructing numerical results to nonlinear fuzzy fractional partial differential equations arising in physical and complex structures.

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