Mechanical Behavior Of Materials

Spray drying is a relatively expensive method of drying, but is particularly recommended when the product is temperature-sensitive (due to the very short time that the product experiences elevated temperatures) or if the typical physical form of a spray dried product (spheroids with a median diameter of up to 250 micron) is desirable. Another advantage of spray drying is that it produces a very homogeneous product from multi-component feedstocks. A prerequisite is that the feed can be pumped and atomized.

Spray drying, with co-current air/feedstock flow, is used extensively within some companies for drying specialty products (dyes, pigments, intermediates, surfactants, ceramics, biodegradable polymer). Target moisture contents down to about 0.1% can be achieved ......

This research work investigates graphite-epoxy design for light weight high performance structure of an aircraft wing spar using computational techniques. MATLAB MuPAD software was used to derive analytical models for the aircraft wing loads using symbolic computation to estimate shear and bending moment forces acting on the wings while ANSYS 14 Mechanical APDL software was used to design and analyze the modeled composite structures of the wing spar. To carry out progressive failure analyses of the various graphite-epoxy composite wing spar designs under bending moment, finite element analysis with ANSYS 14 Mechanical APDL software was employed to determine which spar design would best withstand the bending moment of 10,000Nm generated from the MATLAB MuPAD software. The investigation revealed that all the three designs of Low Modulus (LM) spar, High Modulus (HM) spar and Ultra Modulus (UM) spar failed at 16,801.8 N/m 2 which is above the wing bending moment with ultra-modulus spar having the least deflection of 0.143× 10 −3 m because of its high stiffness property.

Because of their mechanical properties and low density, flax fibers seem to be competitive with glass fibers. However, these fibers present a non-uniformity in many of their characteristics (non-constant diameter along the fiber, variable length, presence of defects). This leads to a dispersion of their mechanical properties. This study focuses on the development of fully biodegradable green composites based on poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) matrix reinforced by flax fibers to determine their elastic characteristics and to analyze their tensile and flexural failure in order to evaluate the influence of the processes on the mechanical properties. The main task is to incorporate flax fibers of several millimeters into the polymer matrix and study of the influence of the twin-screw extrusion and single-screw extrusion which are used for the elaboration of the compound and after the injection of the materials. The first objective is to identify the optimal parameters of the manufacturing processes which permit to elaborate satisfactory products presenting acceptable mechanical properties. The study aims to understand the effect of the introduction of flax reinforcements from a thermal and mechanical point of view. From the main results, the thermal analyses show that the introduction of 20% PBS into the PLA matrix improves the thermal stability of PLA and increases the onset temperature of decomposition. The mechanical characterizations have shown that the stiffness of the resulted composites has been improved after the incorporation of the flax fibers from 1457MPa to 4353MPa compared to the matrix. On the contrary, a decrease in deformation rate was observed owing the addition of flax fibers from 4.4% to 1.9%. These preliminary results show the possibility to develop new bio-composites which are thermoplastic, recyclable, with configurable mechanical properties depending on the selected matrix.

Nanostructuring metals through nanograins and nanotwins is an efficient strategy for strength increase as the mean free path of dislocations is reduced. Yet, nanostructures are thermally often not stable, so that the material properties deteriorate upon processing or during service. Here, we introduce a new strategy to stabilize nanotwins by an interfacial nanophase design and realize it in an interstitial high-entropy alloy (iHEA). We show that nanotwins in a carbon-containing FeMnCoCrNi iHEA can remain stable up to 900 °C. This is enabled by co-segregation of Cr and C to nanoscale 9R structures adjacent to incoherent nanotwin boundaries, transforming the 9R structures into elongated nano-carbides in equilibrium with the nanotwin boundaries. This nanoscale 9R structures assisted nano-carbide formation leads to an unprecedented thermal stability of nanotwins, enabling excellent combination of yield strength (~1.1 GPa) and ductility (~21%) after exposure to high temperature. Stimulating the formation of nano-sized 9R phases by deformation together with interstitial doping establishes a novel interfacial-nanophase design strategy. The resulting formation of nano-carbides at twin boundaries enables the development of strong, ductile and thermally stable bulk nanotwinned materials.

A novel high-performance polyamide 6, polyacrylonitrile and polyvinylidene fluoride nanofibers were fabricated using industrial production Nanospider equipment for liquid filtration as microfilters. The application of nanofibers has been hindered by their poor mechanical strength. This work developed a feasible approach to preparing mechanically strong nanofiber webs. The mechanical strength of the nanofibers was enhanced using special lamination technique on a supporting layer. Experimental results show that the mechanical strength of the nanofibers enhanced more than 5 times while high porosity and liquid permeability retain. The separation results indicate that nanofibers have a potential to be used in liquid filters.

The static fracture toughness of a series of eutectic Al-Si casting alloy with different microstructural features has been evaluated. The dominant influence of eutectic silicon in controlling the fracture toughness is thus clarified. The relationship between the fracture toughness and the microstructure was established. Fracture toughness was found to be strongly associated with the size and morphology of silicon particles. The other feature which greatly influences the fracture toughness is the ratio (/DE)Si, i.e. the silicon particle spacing divided by the equivalent particle diameter, rather than the silicon particle spacing, Si. Fracture toughness also correlates well with the void growth parameter, VGP (=y (/DE)Si), proposed by the authors. The results of the present work can be used to develop an understanding of the variation of fracture toughness with the microstructural features of eutectic Al-Si alloys.

The Brazilian test is the most used test to determine the indirect tensile strength for brittle materials like concrete. ... ........ The results showed that to obtain a meaningful and validated test with the most accurate indirect tensile strength, it is recommended to take a loading arch 2 alfa >= 20° for the concrete and 2 alfa >= 10° for the mortar.

— In the present work external centerless grinding machine, the manual feeding of work pieces can be replaced by designing and development of automatic feeding system which helps to feed the work pieces automatically into the centerless grinding machine. After grinding of the work piece automatic unloading can be done and finally collected in the tray. All the parts and assembly modeling of automatic loading and unloading system using CATIA V5R19.The cycle time analysis result shows to find the number of work pieces grind per minute and also show how the process takes place with respect to the time.

As a part of the framework of the development of ceramic products, scientific research continues this idea that clays are essential vehicles for local development in Africa; and therefore they deserve to be made profitable. This scientific work has the advantage of providing a solution to the housing of the Sahel area. On the other hand, this study can effectively serve as the basis of data in the formulation of ceramics from clay Maroua, in the region of the Far North Cameroon, for a large-scale industrial operation. Thus, two samples of materials respectively KO1 and IP2 have been the subject of a preliminary chemical and mineralogical size rheological study. Once formed, the tubes containing the KO1 and PI2 materials have undergone heat treatment at successive temperatures of 900˚C, 1000˚C and 1100˚C. The baked products obtained have also been the subject of a study of resonance, coloring density, loss on ignition, water absorption, linear shrinkage, porosity and mechanical compression.

The paper presented here approaches to solve the complexity of an anthropomorphic robotic hand. Robotics is now the most advancing field and there has always been an intention of mimicking human-like actuation and behavior. An anthropomorphic hand is one of the approaches to imitate human-like operations. In this paper, the idea of developing an anthropomorphic hand with 15 degrees of freedom and 5 actuators has been elaborated as well as the mechanical design, control system, composition, and peculiarities of the robotic hand have been discussed. The hand has an anthropomorphic appearance and also can perform human-like functionalities, for example, gripping and hand gestures representation. The results reveal that the hand is designed as one part and does not need any kind of assembly and it exhibits an excellent weight lifting capacity, since it is made of flexible thermoplastic polyurethane (TPU) material, and its elasticity also ensures that the hand is safe for interacting with humans as well. This hand may be used in a humanoid robot as well as a prosthetic hand. The limited number of actuators makes the control simpler and the hand lighter.

The paper presented here approaches to solve the complexity of an anthropomorphic robotic hand. Robotics is now the most advancing field and there has always been an intention of mimicking human-like actuation and behavior. An anthropomorphic hand is one of the approaches to imitate human-like operations. In this paper, the idea of developing an anthropomorphic hand with 15 degrees of freedom and 5 actuators has been elaborated as well as the mechanical design, control system, composition, and peculiarities of the robotic hand have been discussed. The hand has an anthropomorphic appearance and also can perform human-like functionalities, for example, gripping and hand gestures representation. The results reveal that the hand is designed as one part and does not need any kind of assembly and it exhibits an excellent weight lifting capacity, since it is made of flexible thermoplastic polyurethane (TPU) material, and its elasticity also ensures that the hand is safe for interacting wit...

— Conditioning of air is not a new process; In the early centaury before 2000 for air conditioning we are using R-22 difluoromonochloromethane. The application of this refrigerant is obsolete in developed countries and also in most of developing countries due to high ozone layer depletion and high global warming potential. But after Montreal Protocol treaty the gas R-22 is to be phased out due to high ozone depletion properties. The developed countries phases out this refrigerant by 2020 and developing by 2030. Now a days we are using R-410A hydro-fluocarbon (HFC) mixture of difluoromethane and pentafluroethane 50%-50% by weight, which is mostly used in industries now a days it has many advantages over R-22 it has no ozone layer depletion but has high global warming potential another eco-friendly refrigerant CO2 which is very cheap as compared to R410A which has low ozone layer depletion and low global warming potential.CO2 has high refrigeration capacity up to 4-5 times than R-410A and also has high heat transfer in evaporator and condenser due to high pressure & density. In this work we are calculating the coefficient of performance, refrigeration effect with different refrigerant under different environment condition and made conclusion that either CO2 would we used as a refrigerant or not.

Piezoelectric materials are widely referred to as “smart” materials because they can transduce mechanical pressure acting on them to electrical signals and vice versa. They are extensively utilized in harvesting mechanical energy from vibrations, human motion, mechanical loads, etc., and converting them into electrical energy for low power devices. Piezoelectric transduction offers high scalability, simple device designs, and high‐power densities compared to electro‐magnetic/static and triboelectric transducers. This review aims to give a holistic overview of recent developments in piezoelectric nanostructured materials, polymers, polymer nanocomposites, and piezoelectric films for implementation in energy harvesting. The progress in fabrication techniques, morphology, piezoelectric properties, energy harvesting performance, and underpinning fundamental mechanisms for each class of materials, including polymer nanocomposites using conducting, non‐conducting, and hybrid fillers are d...

A detailed study was carried out on crankshafts used in two wheeler made from C45 (EN 8/AISI 1042) steel. Undesirable noise was heard in crankshaft when the engine is in running. This was stated as failure of crankshaft. Material has been peeled off and seemed to be scraped at the central portion of the crankpin.  It was the bearing seating place where oil hole also provided. Under analysis the crankpin was identified as tempered. Chemical composition, micro-hardness and microstructure were studied and compared with the specified properties of the crankpin material. Reason for failure is identified as wear due to lower hardness, improper lubrication and high operating oil temperature.

In this study, we investigated natural convection heat transfer from horizontal cylinders with longitudinal plate fins adapted for dissipating heat on a LED (light emitting diode) light. The numerical results were validated with experimental results and a good agreement was found. Parametric studies are conducted to compare the effects of three geometric parameters and a single operating parameter (heat input) on the thermal resistance and the average heat transfer coefficient for the heat sink array.

Vickers microhardness (HV 0.1) and Young's modulus (E) measurements of LWR UO2 fuel at burn-up > 60 GWd/tHM are presented. Their ratio HV0.1/E was found constant in the range 60-110 GWd/tHM. From the ratio and the microhardness values vs porosity, the Young's modulus dependence on porosity was derived and extended to the full radial profile, including the high burn-up structure (HBS). The dependence is well represented by a linear correlation. The data were compared to fuel performance codes correlations. A burn-up dependent factor was introduced in the Young's modulus expression. The modifications extend the experimental validation range of the TRANSURANUS correlation from unirradiated to irradiated UO2 and up to 20% porosity.
First simulations of LWR fuel rod irradiations were performed in order to illustrate the impact on fuel performance. In the specific cases selected, the simulations suggest a limited effect of the Young's modulus decrease due to burn-up on integral fuel performance.

This thesis describes a series of experiments on oxidising sandstone from a yard owned by the City of Sydney Council which is part of the old Saunders Quarries; Hell Hole, which was shut down 130 years ago. These tests were conducted to characterize the properties of the stone in order to determine whether the stone is of adequate quality for the restoration of Heritage-listed sandstone buildings such as Town Hall. The tests conducted include bulk specific gravity, water absorption, compressive strength, rupture of modulus test (flexural tensile strength), Brazil test (splitting tensile strength) and soundness (or salt attack). Brazil testing was conducted also on the quartz-rich specimens from the University of Sydney Clock Tower to provide a comparison of sandstone used in a Heritage-listed building. Petrographic analysis was also conducted on both sandstones to determine the microstructure and mineral composition and to find reasons for the behaviour of the stones in the different tests.
Though the sandstone from Hell Hole met the requirements for bulk density and water absorption, its failure to meet the other requirements, especially in wet conditions, as well as its friability and weathering observable from the petrography, means that it cannot be recommended for use in the restoration of Town Hall.

Information Contained in this work has been obtained by the American Society of Mechanical Engineers from sources believed to be reliable.
However neither ASME nor its authors or editors guarantee the accuracy or completeness of any information published in this work. Neither ASME nor its authors and editors shall be responsible for any errors, omissions or damages arising out of the use of this information. The work is published with the understanding that ASME and its authors and editors are supplying information but are not attempting to render engineering or other professional services. If such engineering or professional services are required, the assistance of an appropriate professional should be sought.

Recent advances in computational techniques and software often allow a rapid assessment of distillation requirements. If the system being studied is close to ideal, for example, a mixture of hydrocarbons, such an approach may suffice for final design purposes.

However, for non-ideal systems or for the development of a new process or product where vapor-liquid equilibria data are scant or absent a different approach should be adopted. In these circumstances it is necessary to simulate the separation by means of a laboratory distillation.

A laboratory distillation can also prove useful in:

(a) providing material for product evaluation studies;

(b) gathering information on suitable materials of construction;

(c) observing the build-up of minor impurities in the system;

(d) determining the height equivalent to a theoretical plate for a given packing/system.

Cartridge brass undergoes significant changes in mechanical properties as a result of cold work. These changes are effectively reversed in the annealing process returning the metal to its precold-worked state. The major goal of this study is to characterize how the variables of annealing time, temperature, and degree of cold work affect the physical properties of cartridge brass. Tensile tests, hardness tests, and metallographic examination are used in conjunction to assess mechanical and microstructural changes brought on by cold work and annealing. Results indicate that mechanical changes from cold work are more prominent during the first stages of cold work. The time to reach recrystallization is reduced in response to increases in annealing temperature as well as increasing cold deformation. The recrystallization temperature is reduced when time of anneal is increased or degree of cold work is increased. Therefore, recrystallization is driven by strain imposed on the metal during cold working and is a thermally activated process.

Electric heaters are used in the process industries for some duties as alternatives to fluid heated or fired process exchangers. When specified and used properly, electric heaters will last for many years without problems. However, there are special features to consider in specifying and operating electric heaters, which, if not understood, can result in damage to the equipment leading to early burn-out of the elements or potentially hazardous equipment failure.

Corrosion induced failure of buried ferrous pipelines causes significant economic losses to the world. Many of the existing buried water pipelines are made of ductile iron in most of the developed countries. Literature shows that the research on the corrosion-induced degradation assessments of ductile iron pipelines is limited and mostly deals with the physical deterioration i. e., loss of wall thickness determined by short-term research. This paper addresses this gap and presents a comparatively long-term study on the corrosion and its subsequent effect on the composition and nanomechanical properties of buried ductile iron pipelines in the accelerated corrosive environment. For experimentation, ductile iron specimens were immersed in the acidic simulated soil solution for 365 days. Physical deterioration assessment over the time was carried out in terms of corrosion rates measured at intervals of 180 and 365 days. A significant change in the percentage composition of key elements and phases were quantified. Furthermore, the mechanical properties of the grains were found to be considerably reduced after 365 days of immersion in the acidic environment by the nanoindentation technique. The results revealed an alarming increase of structural degradation at nano scale for some of the grains due to chloride induced localised corrosion. The significance of the current research is its in-depth analysis of the corrosion-induced degradation of ductile iron pipes which enhances the knowledge related to the failure of these pipelines.

In this experimental study, glass fiber reinforced epoxy composite samples were prepared for tensile and impact strength analysis. Woven roving mats (E-glass fiber orientation 0/90 degree , 300g/m2) were cut in measured dimensions and a mixture of Epoxy Resin (CY-205, Density-1.27gm/cm3), Hardener (HY 951, Density- 0.94 gm/cm3) and Acetone [(CH3)2CO, M= 38.08g/mol] was used to manufacture the glass fiber reinforced epoxy composite by hand lay-up method. The ratio of epoxy: hardener: acetone was varied and the tensile and impact strength of the specimen were compared.

Crankshaft is one of the critical components of an IC engine, failure of which may result in disaster and makes engine useless unless costly repair performed. It possesses intricate geometry and while operation experiences complex loading pattern. In IC engines, the transient load of cylinder gas pressure is transmitted to crankshaft through connecting rod, which is dynamic in nature with respect to magnitude and direction. However, the piston along with connecting rod and crankshaft illustrate respective reciprocating and rotating system of components. the dynamic load and rotating system exerts repeated bending and shear stress due to torsion, which are common stresses acting on crankshaft and mostly responsible for crankshaft fatigue failure. Hence, fatigue strength and life assessment plays an important role in crankshaft development considering its safety and reliable operation. The present paper is based on comparative studies of two crankshafts of fatigue life assessment of a single cylinder diesel engine crankshaft by using High cycle fatigue (HCF) technique

This Process Engineering Guide is one of a series on heat transfer produced for GBH Enterprises. It is intended to provide guidance in the estimation of batch heating and cooling times and the design of heat transfer equipment for this purpose.

This Guide gives methods for estimating the batch heating or cooling times for cases where the heat transfer performance of the system may be estimated. Alternatively, it may be used to specify the required heat transfer performance of the system in order to meet a given heating or cooling time.

It does not give detailed advice on the estimation of heat transfer coefficients nor the design or rating of heat transfer equipment. Information on this topic may be found in other guides in the GBH Enterprises heat transfer series.

In LT PEM fuel cells Platinum used as a catalyst for the splitting of gases is very costly and it is very sensitive to CO poisoning.

Recent studies have invented a proton conductive polymer for the usage of HTPEM fuel cells.
There is a tremendous potential in these membranes for further research. They have been proven to tolerate up to 3% CO.

This book is designed to help the engineer understand the principles of metal forming and to analyze forming problems – both the mechanics of forming processes
and how the properties of metals interact with the processes. In this book, an entire
chapter is devoted to forming limit diagrams and various aspects of stamping and
another to other sheet forming operations. Sheet testing is covered in a separate
chapter. Coverage of sheet metal properties has been expanded. Interesting end of-chapter notes have been added throughout, as well as references. More than
200 end-of-chapter problems are also included.

There has been growing interest in graphene and its remarkable properties since its discovery. Many attempts have been made to use graphene as a reinforcement material in composites rather than a bulk material; this is because of its high cost and manufacturing limitations. This paper speculates the use of Graphene powder to enhance properties of Epoxy Resins. It focuses on highlighting the development and basic construction of various types of composites and it presents the findings of an experimental development of Epoxy Nano-Composite reinforced with Graphene powder and also compares the result with non-reinforced Epoxy test samples. A detailed procedure is provided and conclusions are drawn on the interpreted results. Some suggestions, to get better results, are also highlighted.

This guide covers the mixing of solid-liquid systems; it deals with suspending particulate solids in a liquid, but does not cover slurries and other non-Newtonian solid-liquid systems.

The aim of this guide is to cater for the majority of mixing duties for particulate solids in liquids. For more specialized duties, reference should be made to the GBHE Mixing and Agitation Manual and, if appropriate, to one of the experts.

— In this research paper we talk about various type process for pressure die casting like cold chamber die casting and hot chamber die casting and major problem occurred during process on aluminium alloy during process. Casting defects are irregularities in the material that have a negative influence on the component; either it is caused from material failure, construction errors or as an effect of process parameters. Defects depend on several factors both in the material, for example the alloy, as well as the surrounding environment such as weather conditions. In the die casting industry today there are many cast defects like shrinkage, porosity and gas blow.