International Journal of Materials and Product Technology (14 papers in press)
Finite Element Analysis to Study the Shearing Mechanism in Punchless Electromagnetic Perforation of Aluminium Tubes
by Sagar Pawar, Ravi Valecha, Sachin Kore
Abstract: Electromagnetic perforation is a method of producing holes in a workpiece based on electromagnetic effect, which uses a Lorentz force as a driving force produced due to the interaction of magnetic fields generated in the solenoid and conductive workpiece. The motivation behind this research is to study how the disadvantages of conventional shearing processes like, the formation of burrs and slivers are overcome by electromagnetic perforation and how it can be used to shear the lightweight materials which are having an increasing demand in automobile and aerospace industry. Electromagnetic manufacturing is one of the well-known technologies for forming aluminum alloys. In the present research work, a novel approach for modeling the electromagnetic perforation has been used to study the shearing mechanism involved, optimum energy and the pressure required for perforation. The complete finite element analysis of EM perforation is conducted in two steps. Firstly, for the calculation of transient magnetic pressure generated due to an interaction between magnetic fields present in coil and tube, for this, a coupled simulation model is developed in LS-DYNA software. The generated magnetic pressure causes the expansion of the tube, resulting in crack initiation near the die cutting edge and subsequent perforation of the tube. In the second step, to study the detailed shearing mechanism involved during the EM perforation process obtained transient pressure is used for 2D FE analysis in Abaqus/Explicit.
Keywords: Finite element analysis; high strain rate shearing; Electromagnetic Perforation; modeling.
Reconfigurable Half-Precision Floating-Point Real/Complex Fused Multiply and Add Unit
by Jean Jenifer Nesam J, S. Sivanantham
Abstract: Multiplication followed by an addition/subtraction is the common operation in many digital signal and image processing applications. This paper presents a reconfigurable floating point Real/Complex-Fused Multiply and Add (R/C-FMA) unit using small precision (IEEE-754-2008 16-bit half-precision) format. The developed FMA can be reconfigurable from real to complex based on the control bits. This architecture performs real FMA, complex FMA or mixed real and complex FMA. The Field Programmable Gate Array (FPGA) implementation of R/C-FMA design, utilizes the modern features of inbuilt DSP blocks for mantissa multiplication and addition/subtraction. The efficient DSP usage for fp16 FMA design shows a 60% reduction in LUT area when compared to conventional fp32 FMA.
Keywords: FMA architecture; floating-point arithmetic; reconfigurable system; VLSI architecture; FFT processor.
Design and Analysis of Majority Logic Based Multipliers in Perpendicular Nanomagnetic Logic (pNML)
by Abhishek Ajith, Sanath Kumar Cheekoti, Marimuthu R, Balamurugan S
Abstract: In the process of finding an alternative for CMOS technology various new technologies have emerged with emphasis on reducing the power consumption. Amongst the various technologies, Nanomagnetic Logic (NML) serves as a favorable replacement. Nanomagnetic Logic is a new computing paradigms for the beyond CMOS technology that uses both memory and logic elements between nanomagnets using field-coupled technology. This paper explores the approximate computing concept in Nanomagnetic Logic. Approximate computing is an emerging computing paradigm where we can trades off the power with accuracy. We have put forward two approximate 8-bit Dadda multipliers that have been designed using two different 5:2 approximate compressors using majority based logic. The effectiveness and efficiency of these multipliers are evaluated using image processing algorithms and comparison with other approximate multipliers.
Keywords: Compressor; Multiplier; Approximate; Dadda Multiplier; Nanomagnetic Logic (NML); image processing;beyond CMOS.
Study on Mechanical Properties of Fabricated Hybrid Natural Fiber Polymeric Composites
by Rajendra Kumar, Ravi Pratap Singh, Ravinder Kataria
Abstract: In the current work, an effort has been made to fabricate the natural fiber hybrid polymeric composites using two natural fibers i.e. shisham wood powder, and rice husk. The injection moulding process is employed to fabricate the different three polymer composites by varying the and fiber size, and fiber weight %. These three fabricated composites have been named as; hybrid-filler polypropylene composites which are separately containing wood powder and talc, rice husk powder and talc, and a mixture of wood powder, rice husk powder and talc. These fabricated specimens are further tested for their tensile, flexural, and impact properties. The experimental results have revealed that the fabricated polymeric composites can successfully be employed to produce stable and strong hybrid polymeric composites for their further industrial applications. The microstructure study of the tested samples has also been undertaken to study the behaviour of the material.
Keywords: Composites; Extruder; Husk; Hybrid; Injection; Microstructure; Moulding; Rice; Wood.
Experimental characterization and modelling of polyethylene terephthalate preform for injection stretch blow moulding
by Davide Battini, Andrea Avanzini, Massimo Antonini, Davide Fausti, Maurizio Mor, Angelo Vertuan, Fabio Chiesa, Marco Grazioli, Giorgio Donzella
Abstract: Polyethylene terephthalate (PET) is a widely used polymer in the production of bottles by injection stretch blow moulding (ISBM). In this work, we present a characterization method to identify material properties directly from a preform, considering temperature and stress-relaxation effects related to its viscoelastic response. A customized oven and gripping system were designed to perform uniaxial tests in a proper temperature range on tubular specimens obtained from preforms. A visco-hyperelastic model is then proposed: a Marlow-type strain energy function coupled with a Prony series and William-Landel-Ferry equation to include time and temperature dependency. Finally, a case study of ISBM process is implemented in a finite element code considering this constitutive model. Strain maps and predicted thickness of the bottle wall were evaluated as process quality indicators. Simulation results showed good agreement with measurements on the real processed bottle, confirming the usefulness of the approach for product or process parameters optimization.
Keywords: Polyethylene terephthalate; PET; bottle; injection stretch blow molding; ISBM; finite element; FEM; experimental characterization.
Analysis on hardware implementations of deblocking filter for video codecs
by Prayline Rajabai C, Sivanantham S
Abstract: H.264 and H.265 are the most popular video coding standards used for various applications. These coding standards use multiple modules to perform video compression. Among the various modules, De-Blocking filter (DBF) is one of the critical modules in the video codec which requires extensive computation. Hence it is computationally complicated and critically time-consuming. DBF removes the blocking artifacts caused due to intra-prediction, inter-frame prediction and motion compensated prediction. For the past two decades, a deblocking filtering algorithm is implemented in hardware and research is still going on for realizing optimized hardware solution for this critical module. Efficient hardware implementation of the DBF is essential for high-resolution video applications such as HDTV to increase the decoding throughput, achieve high speed and to reduce the off-chip memory access cycles. This paper presents a technical review and analysis of various hardware architectures of DBF used for H.264 and H.265 coding standards.
Keywords: VLSI architecture; deblocking filter; H.264/AVC; H.265/MPEG; video coding.
Cost-Efficient Full Adder Designs in Quantum-dot Cellular Automata
by Marshal Raj, Lakshminarayanan Gopalakrishnan
Abstract: Quantum-dot cellular automata has the potential to meet the requirements faced by post-Complementary Metal Oxide Semiconductor technologies. Adder is a key component in any digital circuit system. Several full adder designs are proposed in Quantum-dot Cellular Automata. In this work, all the existing techniques used in Quantum-dot Cellular Automata adders are analyzed and two cost-efficient full adder designs are proposed for different crossover techniques. The proposed designs have fewer cells and delay compared to the existing state-of the art designs. The proposed designs can be extended to implement any N-bit adder. Missing cell defect analysis is done for the proposed designs and compared with the existing state-of-the-art designs. All the designs are implemented and verified using QCADesigner.
Keywords: Adder; Cost; Crossover; Missing cell defect; Quantum-dot Cellular Automata (QCA).
Special Issue on: Advanced Materials in Electrical and Mechanical Applications
Similar Material Development of Seafloor Polymetallic Sulfide
by Ya Xie, Zhonghua Huang, Yingguang Xu
Abstract: This paper focuses on the similar materials development of the seafloor polymetallic sulfide. Uniaxial compression tests and triaxial compression tests were conducted on the seafloor polymetallic sulfide samples to obtain the uniaxial compressive strength, the cohesion and other mechanical parameters. Based on the similar materials model method and similarity conditions, similar materials for seafloor polymetallic sulfide were selected and the composition proportion was determined. The similar materials mainly composed of sand, gypsum and cement. The similar materials were developed and the mechanical properties were tested. Test results show that the cohesion and the internal friction angle which were close the those of the seafloor polymetallic sulfide were 2.447 MPa 38.04
Keywords: Seafloor polymetallic sulfide; simulated materials; deepsea mining.
Deformation Control Method For Inorganic Biological Coating Materials Under Tensile Loading
by Peng Wang, Ningchao Zhang
Abstract: In order to overcome the problem of long control period in traditional material deformation control methods, a new method for controlling the deformation of inorganic biological coating materials under tensile loading is proposed. This method classifies inorganic biological coating materials and studies the properties of different materials. By improving the preparation process of inorganic biological coating material, its strength was enhanced and deformation was restrained. Based on the above materials, the inorganic biological coating material is reprocessed by heat treatment and cold hardening, and the deformation compensation technology is adopted to further control the deformation of inorganic biological coating material. Experimental results show that the method in this paper can reduce the material deformation by 3.34%, and the control effect is good. The control period is always less than 10 hours and the control period is short, which provides an important reference for the optimization of inorganic biological coating materials.
Keywords: Tensile load; Inorganic biological coating materials; Deformation; Control;.
An Abrasion Damage Evaluation Method Of Metal Mechanical Material For Automotive Chassis Based On Wavelet Transform
by Ruibin Jiang, Liangchong Lian
Abstract: In order to overcome the problems of low accuracy and low fitting rate of traditional methods for evaluating abras ion damage of metal mechanical materials, a new method for evaluating abrasion damage of metal mechanical materials of automobile chassis based on wavelet transform is proposed in this paper. This method utilizes the time-frequency joint wavelet feature extraction algorithm and the correlation coefficient algorithm to realize the extraction and selection of damage features. The membership function is constructed by the method of fuzzy statistics to evaluate the abrasion damage of metal mechanical materials in automobile chassis. The experimental results show that the evaluation accuracy of the proposed method is higher than 75%, and the fitting rate is higher than 56%, which proves that the proposed method has better evaluation effect.
Keywords: Automobile; Metal; Machinery; Abrasion damage; Evaluation;.
Adhesion Method Of Advanced Composite Structures For Mechanical Design And Optimization
by Yuanyuan Wang
Abstract: In order to overcome the low degree of fitting between the traditional bonding method and the actual working conditions, a new advanced bonding method for composite structures is proposed. The finite element simulation software NASTRAN was used to construct the finite element model of mechanical structure and obtain the damage form and path of mechanical structure. According to the relationship among adhesive strength, ply sequence and ultimate strength of bonded structure, and the relationship among the thickness of composite patch, stress intensity factor and the number of optimization iterations, advanced bonding criteria for mechanical design and optimization of composite structures are proposed. The experimental results show that the goodness-of-fit index (GFI) of this method is always above 0.92, the normed fit index (NFI) is above 0.96, and the comparative fit index (CFI) is above 0.92, it has the characteristics of feasibility and practicability.
Keywords: Mechanical; Design and optimization; Composite materials; Bonding.
MOGA Optimization of Wear Performance of Stir Cast AA7050/B4C-T6 Ex-Situ Metal Matrix Composite
by Arvind Kumar, Arnab Pal, Ram Naresh Rai
Abstract: Al-5.6Zn-2.1Cu-1.8Mg alloys are high strength Aluminum alloys, commonly used in structural components of automobiles and aerospace. Despite high strength, it has poor wear resistance. The wear resistance of the alloys can be enhanced by incorporating ceramic particles into it by forming composite materials. The present paper explores the AA7050-xB4C-T6 Composite (x= 0,5,10 wt. %) developed through flux assisted stir casting techniques and evaluate the wear performance in terms of wt. loss and coefficient of friction (COF) by the concurrent effect of process parameters such as weight % of B4C, Normal load, and sliding distance using Pin-on-Disc Tribotester. The experiments were designed based on the full factorial design of the experiment. From the analysis of the results, it established that sliding distance has a significant influence on the performance measure. Further study of results shows that the applied load has profound influences on the wt. loss, whereas wt. % of B4C have maximum influence on the COF. The developed quadratic regression model predicts the performance measure with an accuracy of (Adj) R2 value of 0.99048 for wt. loss and 0.96504 for COF. The multi-objective Genetic Algorithm (MOGA) optimization techniques developed to optimize the performance parameters. The % error estimated between optimized and the experimental wt. loss, and COF is 8.13% and 3.58%, respectively. The errors are within the acceptable threshold.
Keywords: AA7050-B4C Composite; Regression model; MOGA; applied loads; sliding distance.
Research On Design And Pressure-Retaining Performance Of The Pressure-Retaining Sampler For Full-Ocean-Depth Sediment
by Shudong He, Youduo Peng, Yongping Jin, Buyan Wan
Abstract: A new type of pressure-retaining sampler(PRS)suitable for full-ocean-depth (11000 m) sediment sampling is proposed. In order to optimize the pressure-compensation device(PCD) of the PRS, the pressure-compensation model (PCM) is established. This model is adopted to study the influence of different factors on the pressure-retaining performance(PRP) of PRS. The results showed the wall thickness of the PCD had little influence on the PRP, but the pre-charging pressure, ambient temperature difference and working volume had great influence on it, among which the pre-charging pressure had the most obvious influence. Then, a test was carried out. Under different pre-charging pressure, the trend of test pressure-retaining rates were consistent with that of theoretical values, and the error between theoretical and test values were within 5%, which validated PCM. The established PCM can provide theoretical basis for the design of PCD, and the designed PRS can provide new guidance for the design of PRSs.
Keywords: full-ocean-depth sediment; pressure-retaining sampler; pressure-retaining performance; pressure-retaining rate.
Special Issue on: New Advances in Topology Optimisation
Multi-objective Topology Optimization Design of Lattice Structures with Negative Poisson's ratio considering Energy Absorption and Load-bearing Characteristics
by Yixian Du, Peng Yin, Qihua Tian, Xiangman Zhou
Abstract: To make lattice structures have both load-bearing and energy absorption characteristics to protect the safety of personnel and equipment in the collision, this paper proposes a multi-objective topology optimization method for the design of lattice structures with negative Poissons ratio. The energy absorption and load-bearing characteristics of the lattice structure are characterized by negative Poisson's ratio and stiffness, respectively. A topology optimization model is established to maximize the stiffness and negative Poisson's ratio of the lattice structure. The design optimization of microscopic material is conducted by the energy homogenization method. A modified optimality criteria method is employed to update design variables. The energy absorption and load-bearing characteristics of the optimized structure are tested and analyzed by finite element simulation and compression experiment, respectively. The results show that the optimized lattice structure has both energy absorption and load-bearing characteristics. In general, the proposed method can provide a feasible reference for the topology optimization design of anti-collision structures.
Keywords: Multi-objective topology optimization;Negative Poisson's ratio lattice structure;Load-bearing characteristics;Energy absorption characteristics.