bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guided Modes in Slab Waveguide with Central Anisotropic Metamaterial Layer
Authors: Salman Hawraa H. , Yasser Hassan A. 
Published: November 2020

Abstract
This work studies the characteristics of TE modes in a three layers slab waveguide that contains an anisotropic metamaterial as a central layer. The results show that all modes except TE
1 achieved forward propagation and then turned backwards. The effective refractive index value at which the propagation type is reversed increases with the mode order and the thickness of the middle layer. In addition, an anisotropic property in the metamaterial layer shift the modes curves (exept TE
1 ) to left or right with respect to the isotropic case. Furthermore, the mode TE
1 is abnormal and inconsistent with the behavior of other modes. Except TE
1 mode, the confinement factor is small in the forward propagation region and reaches large values in the backward propagation region.
Influence of wood minutes (reed) on some physical and mechanical characteristics for (EP+W) composites
Authors: Abed Raya Ali , Al-sarrafand AbdulhameedRaheem , Almaamori Mohammed 
Published: November 2020

Abstract
By using agricultural wastes, the epoxy composites were prepared with reed minutes and with a fixed weight fraction of all samples (30%) and a particle size (212) μm. Preparation of samples carried out by using the casting method. Some mechanical properties have been investigated were included (tensile strength, bending, creep) and the results showed improvement of all properties through increased bending resistance and elasticity increased with epoxy reinforcement with wood particles. The intent of this research is to enhance the mechanical properties by adding agricultural wastes that represented by (reed).
Construction of Scaffold from MgO Nanoparticle: Bone Fracture Healing
Authors: Hassan Marwa Abdul Muhsien , Abbas Asaad M. , Mohammed Ali Mohammed J. 
Published: November 2020

Abstract
Magnesium oxide nanoparticles have been prepared by using chemical method. The chemical analysis of the samples was carried out using EDX measurement. The results showed that all the samples are very pure, consisting of the elements of magnesium and oxygen. XRD pattern of MgO nanoparticles prepared at a different temperature (500, 550 and 600 °C) and 3 hour time. It is seen that the peaks appear at 2θ=36.92 degrees, 2θ=43.02 degrees, 2θ=62.38 degrees, 2θ=74.56 degrees and 2θ=78.48 degrees, reflective planes reflect (111), (200), (220), (311) and (222), respectively. Scanning electron microscope of treated magnesium oxide at different temperatures was carried out. As the result showed that magnesium oxide have spherical nanoparticles in diameters ranging from 15-20 nm, systematically distributed. Histopathological evaluation showed the thick mature threads and anatomizing bone threads filled interface zone in MgO scaffold prepared at different annealing temperatures.
Effect of Gamma Irradiation on the Physical Properties of PVA Polymer
Authors: Jassim Tafahom Ahmed , Saeed Asrar Abdulmunem 
Published: November 2020

Abstract
Polyvinyl alcohol (PVA) films were prepared by casting method. The optical properties was measured in the wavelength rang of (200–900) nm, by using UV-visible spectroscopy. The effect of irradiation lead to degradation on the physical properties such as absorbance, transmittance, refractive index, extinction coefficient in addition of the real and imaginary part of dielectric constant was studied. This study reveals that all these parameters affected by the increasing of them irradiation, and also found that the optical energy gap has been increased with the increasing of the irradiation. The structural properties are studied by using XRD, FTIR spectrum, and FESEM.
Electron Stopping Powers of Chitin and Chitosan
Authors: Abdul Muhsin Zahraa A. , Aldhamin Ahmed Saad , Shafik Shafik S. 
Published: November 2020

Abstract
Chitosan can be deduced from chitin by simple chemical process. Chitosan has many applications and one of the promise application is used as nuclear shield by adopted it with some materials. Electron stopping power (SP) represents important parameter in tested the ability of any material to use it as nuclear shield. Therefore, stopping powers of electrons incident with different energies on chitin and chitosan have been calculated by using codes of National Institute of Standards and Technology (NIST) after modified it by built in the chemical structure and some other properties of chitin and chitosan in the codes. The results of total SP showed that chitosan has values larger than chitin but the differences are small and the maximum percentage difference ratio is 6.8% at 4 MeV electron energy. Total SP has approximately 35 Mev.cm2/g at 0.01 MeV electron energy, and decreasing with energy till to 1 MeV, then slowly increasing. In addition to total SP, the collision SP, radiative SP, density effect parameter, radiation yield, and electron range were calculated. The behaviors of the calculated parameters have been studied and explained. The obtained results suggested that chitosan may be used after mixing it with other materials as a shield from nuclear radiation, especially in low energies.
Properties of O(6)-U(5) transition symmetry for 122-124Cd isotopes in IBM
Authors: Kassim Huda H. , Abd-Aljbar Alyaa A. , Al-Jubbori Mushtaq Abed , Abdullah Hewa Y. , Hossain I. , Sharrad Fadhil I. 
Published: November 2020

Abstract
The some properties, Energy levels, B(E2) values and potential energy surface, for even-even 122,124Cd isotopes have been studied using the interacting boson model. The predicted levels (energies, spins and parities) and B(E2) values results were reasonably consistent with the experimental data. The contour plot of the potential energy surfaces shows all interest nuclei were deformed and have O(6)-U(5) transition symmetry.
Effect of laser fluencies on solar cell characterization of (CdO)1-x:Sbx/PSi thin films by laser induce plasma
Authors: Dwech Majed H. , Aadim Kadhim A. , Jihad Ghaith H. 
Published: November 2020

Abstract
In this paper, Cadmium Oxide: Antimony has been deposited on porous silicon substrate using laser induces plasma technique. The solar cell parameters fill factor and efficiency; have been analyzed through changing of laser energy. The results shown that the change in electron mobility resulting from the change in laser energy leads to significant improvement in fill factor and efficiency. Moreover, there is slight improvement in the efficiency of CdO: Sb/Psi solar cell as a result of changing the thickness of CdO: Sb.
Investigation on water as lubricant in combination with a structured tool surface in micro metal forming
Authors: Rathmann L , Czotscher T , Radel T , Vollertsen F 
Published: November 2020

Abstract
The use of lubricants in forming processes is common because they reduce friction between the tools and workpiece during the forming process. Today, mainly mineral oils are used as conventional lubricant. In order to cut their amount in the future, the friction between tools and workpiece is investigated by using water as lubricant in this work. Therefore, the tools’ surfaces are structured with laser induced periodic surface structures (LIPSS) to make them hydrophilic and strip drawing tests are carried out at different traverse velocities to evaluate the resulting friction force. The results show that at a traverse velocity of v = 10 mm/s the maximum friction force is lowest for the structured tool with water (F = 7.0 N) in comparison with unstructured tools in combination with a conventional lubricant. Consequently, the potential of water as lubricant combined with a hydrophilic surface structure is highlighted.
Influence of anisotropy evolution on strain path independent failure limits
Authors: Bandyopadhyay K , Basak S , Lee M G 
Published: November 2020

Abstract
Stress based forming limit diagram (SFLD) and polar effective plastic strain (PEPS FLD) diagram are two techniques reported to be independent of strain path change. Thus, these techniques are capable of predicting failure in pre-strained sheet metal samples. Therefore, in this study evolution in anisotropy properties of sheet metals were considered in terms of evolution in yield shape during conversion of conventional strain based forming limit diagram (FLD) to SFLD and PEPS-FLD. The evolution in anisotropic properties were modelled as a function of effective plastic strain depending on which the anisotropic coefficients of non-quadratic yield model Yld2000-2d were calculated. Further, to analyse the strain path change effect, metal sheets of extra deep drawing quality steels were first deformed under biaxial condition in Marciniak in-plane stretch forming setup. The pre-strained samples were subsequently deformed with hemispherical punch till the necking appears. For failure prediction, finite element modelling of the complete procedure was performed considering evolution in the yield shape. Finally, both the failure criteria were implemented for failure prediction. Implementation of the evolution in yield function in finite element analysis and failure criteria provided better results.
Determination of the properties of semi-finished parts in blanking processes
Authors: Wiesenmayer S , Frey P , Lechner M , Merklein M 
Published: November 2020

Abstract
Deviations of the properties of semi-finished sheet metal parts affect the finished part’s geometry and its properties. With knowledge of the deviations, forming processes can be adjusted to a certain degree in order to maintain the part quality. Typically, in mass production, the sheets are blanked before deep drawing. Within the blanking processes, the necessary cutting force and cutting stroke are both influenced by the properties of the material. Thus, by the analysis of the process data, which is obtained in blanking processes, deviations of the properties of semi-finished parts could be determined. Within the scope of the work, it is analyzed to which degree process data, which is gained during blanking processes, can be used for the determination of the properties of semi-finished parts and their deviations. For this purpose, a blanking process is investigated for two different batches of the dual phase steel DP600 with a nominal sheet thickness of 2.0 mm and varying mechanical properties. In addition, the sheet thickness of the specimens is reduced by 5 and 10 % for one batch. The recorded process data from the blanking process is correlated with the properties of the sheet materials, which are determined with uniaxial tensile tests.
The effect of friction and lubrication modelling in stamping simulations of the Ford Transit hood inner panel: a numerical and experimental study
Authors: Berahmani S , Bilgili C , Erol G , Hol J , Carleer B 
Published: November 2020

Abstract
Reducing weight of Body in white (BIW) is a well-known solution to tackle environmental issues in automotive industry. Replacing steel by lighter aluminium sheet material is an accepted alternative. However, this trend brings challenges like the forming of Aluminum into complex car body parts. These challenges signify the necessity of more advanced tools to obtain defect-free parts. Nowadays, it is a common practice to implement forming simulations at the early stage of part design in order to identify critical features and to optimize the production process. Although, it is known that friction and lubrication conditions are one of the most influential sources affecting product quality in aluminium sheet metal forming, it is currently not considered in detail in stamping simulations. The current application case focuses on the role of friction and lubrication modelling in stamping simulations of an aluminium hood inner part of the new Ford Transit. A comparison was made between different friction models to identify and resolve split issues in the forming simulations. Simulation results were used to guide try-out towards efficient and successful elimination of these issues on the physical panels. Finally, different possible scenarios corresponding to production conditions were investigated to define a robust process window.
Soft sensing force measurement approach in sheet metal forming facilities
Authors: Olaizola Jon , Iturrospe Aitzol , Abete Jose Manuel , Galdos Lander , Argandoña Eneko Sáenz de 
Published: November 2020

Abstract
Process stability and facility security are the two main purposes for measuring the force in sheet metal forming facilities. These two purposes look for guaranteeing the good health of the facility avoiding overloads and at the same time look for variations in the process force that could lead to products out of the demanded quality. Traditionally there have been different approaches to measure the force exerted by the press. Piezoelectric sensors and strain gages are the most widely used technologies. However there are some common limitations that reduce the success in the measurement of the force by the aforementioned sensors: force sensors tend to have a signal drift and the introduction of the sensors together with the electronics represents an extra cost that in some cases can be high. As an alternative to the implementation of force sensors, soft sensing approaches take advantage of the already available signals in the facility to estimate non measured variables, the force in this case. The present work aims at predicting the force curve that a servo press exerts in forming processes reading the internal servomotor signals. The approach has been evaluated with several forming processes achieving an error lower than 3% for all the cases.
Identification of methods for the in-situ measurement of cutting forces in a tool-bound punching machine
Authors: Niessner S , Liewald M 
Published: November 2020

Abstract
With the increasing implementation of industry 4.0 technologies in production plants, issues such as control and monitoring as well as feedback control of plants and processes are becoming more and more important in current development trends. Thereby, potential approaches to such issues are generally accompanied by an increased use of sensors in production systems, aimed at gaining operation-, product- and process-specific data. In this respect, this paper focusses on the shear cutting process of a tool-bound punching machine. One of the most important parameters for the evaluation of shear cutting processes is the cutting force required. However, the precise measurement of this highly dynamic process parameter proves to be relatively challenging. The limited installation space within the tools and the loads caused by highly dynamic axis movements decisively restrict the options for sensor-based process monitoring. In order to face these challenges during sensor implementation in such punching machines, issues regarding measuring concept, localization and resulting measurement deviation of the sensors have to be solved simultaneously. In this paper, relevant measurement concepts and their properties are discussed, and the most favourable integration possibilities are derived. Based on this, several measurement concepts are identified that could be suitable for the application considered. These measuring methods include hydraulic pressure sensors, strain gauges or piezoceramics. The major contribution of this paper is an experimentally conducted systematic comparative study of these methods, in which the accuracy of the sensors used is evaluated and the influence of different integration positions on the measurement result is investigated.
A pressure-coupled Drucker function for plasticity and fracture modelling of AA5182
Authors: Zhang Chong , Wang Yue , Lou Yanshan , Fu Lei , Zhang Saijun , Yoon Jeong Whan 
Published: November 2020

Abstract
In this paper, a pressure-coupled Drucker function is proposed to model the plastic deformation and fracture from shear to plane strain tension of AA5182 sheet. Experiments are conducted for AA5182 in shear, uniaxial tension and plane strain tension, and the force-stroke curves are measured during the tests. The plastic deformation is modeled by the Drucker function. The Drucker function is modified to consider the pressure effect for fracture limit stress prediction of the alloy. The pressure-coupled Drucker function for plasticity and fracture is calibrated by an inverse engineering approach. The calibrated plasticity models are then applied to numerical prediction of plastic deformation of the alloy under various loading conditions. It is observed that the pressure coupled Drucker function accurately describes the plastic deformation under large plastic deformation as well as the onset of ductile fracture under these loading conditions.
Influence of anisotropic yield criteria on simulation accuracy of the hole-expansion test
Authors: Panich S , Chongbunwatana K 
Published: November 2020

Abstract
Prediction accuracy of the two well-known anisotropic yield criteria, namely, Hill’48 and Yld2004-18p, on plastic deformation of AA5052-O sheet aluminium alloy experiencing compound stress was profoundly examined and contrasted in this work. To obtain the flow behaviour and anisotropy of the test material in varying loading directions, both uniaxial tensile and balanced-biaxial tests were conducted in the corresponding directions. Furthermore, a disc-compression test was carried out to reveal the biaxial r-value. Those gained mechanical properties could therefore be used to determine the material constants required by each yield criterion. The standard conical-punch hole expansion test was chosen here to impose complex stress on the sheet specimen. Forming parameters such as the punch load, stroke paths, hole expansion ratio, sheet thickness profile around the hole circumference and flange height were all monitored and investigated. It was shown that the results from the Yld2004-18p model with an exponent of eight apparently better agreed with the experimental data than those from the Hill’48 one. A conclusion could be drawn here that the yield criterion significantly affected the accuracy of the predicted deformation behaviour of the investigated aluminium alloy grade AA5052-O nevertheless in dependence on the degree of material anisotropy.
Measurement-based evaluation of interfacial polymer layer inserted in sound deadening laminated sheet
Authors: Park Hyeonil , Kim Se-Jong , Lee Jinwoo , Kim Daeyong 
Published: November 2020

Abstract
Mixed mode bending (MMB) test associated with measurement of crack tip opening displacement (CTOD) is a practical method to experimentally evaluate mixed-mode cohesive zone model (CZM) properties of polymer layers in various mixed-mode ratios. However, it has an obvious limitation that does not allow for plastic bending of adherends during the tests, making it difficult to evaluate the polymer layer inserted in the sound deadening laminated sheet (SDLS) comprising thin metal sheets which are vulnerable to the plastic bending. This paper provides an experimental technique to suppress the plastic bending of the thin metal sheets during the MMB test. Supporting tools were designed, and bonded to the both outer surfaces of the SDLS. Until delamination occurred, the evolution of fracture toughness (G) was evaluated, and the CTOD was measured in the stereo image using a digital image correlation system. Finally, the mixed-mode CZM properties was successfully established based on the differentiation of the relation between the evolution of G and CTOD.
The determination of friction coefficient in Nakazima test and its application in predicting FLCs with modified M-K model
Authors: Wang Yubao , Zhang Cunsheng 
Published: November 2020

Abstract
In this work, the friction coefficient between the punch and the specimen during the Nakazima tests is determined by comparing the experimental and the numerical strain paths. Afterwards, the FLCs of the Al-Mg-Li alloy sheet are predicted with the modified M-K model, which considers the through-thickness normal stress and the friction through introducing the expressions of the normal stress and the friction stress into M-K model. Finally, the predicted FLCs of the sheet are compared with the forming limits determined by Nakazima tests.
Material testing of magnesium alloy AZ31B using a finite element polycrystal method based on a rate independent crystal plasticity model
Authors: Vago Giorgio , Oya Tetsuo 
Published: November 2020

Abstract
Magnesium and its alloys are attractive structural light materials because they have a high spe-cific strength and high specific stiffness. That is why their usage in high performance automotive and aerospace applications has been increased. However, their high anisotropy and low ductility could bring to forming failure, to avoid these a better accuracy for metal forming simulation is re-quired. The identification of macroscopic parameters is expensive due to the experiments needed to find them, the use of multi-scale approach allows to find parameters for the model through easier experiments. A finite element polycrystal method, based on a rate independent polycrystal plasticity model, is implemented in order to perform the material testing of a cast magnesium alloy AZ31B. The parameters of the model are adjusted to better fit the experimental data through a trial and error process.
Inferring the surface roughness of Al-Si coated 22MnB5 steel using an in situ laser speckle characterization technique
Authors: Klassen C M , Emmert J , Daun K J 
Published: November 2020

Abstract
Hot stamping of aluminium-silicon (Al-Si) coated 22MnB5 steel blanks is widely used in the automotive industry to produce light yet crashworthy parts. However, the coating melts at ∼577°C and transforms into a rough intermetallic layer as iron from the base steel diffuses towards the surface. The blank surface roughness impacts the radiative properties during heating as well as weldability, paint adhesiveness, and cooling rate during forming and quenching. This study pioneers the use of laser speckle patterns, caused by the constructive and destructive interference of collimated light reflected off the blanks, to infer the evolving surface roughness of Al-Si coated steel coupons in situ. The results reveal a significant increase in surface roughness once intermetallic compounds reach the surface and that higher furnace set-points produce rougher parts.
Numerical and Experimental Investigation on Hot Stamping of TWB B-Pillar
Authors: ChiuHuang Cheng-Kai , Chiang Ming-Feng , Lee Ping-Kun 
Published: November 2020

Abstract
In order to achieve the targeted crashworthiness performance, the application of Tailor-Welded-Blank (TWB) on the crash-relevant components has become a trend in the automotive industry. This paper aims to investigate the mechanical property and structural performance of the hot stamped TWB B-pillars. After hot stamping, the strength grade for the hard zone is 1500 MPa while the soft zone’s strength grade is 590 MPa. The CAE model shows that the intrusion distance is decreased for the TWB design compared to the monolithic material B-pillar. The three point bending performance could be adjusted by changing the range of the soft zone. It is observed that the weld line has a low crack sensitivity during hot stamping. The transition zone between the hard zone and soft zone is less than 1mm. The ATOS scanning results show that no significant effect on the part’s size deviation for the TWB design compared to the monolithic material B-pillar.