Potential of Bio-Inspiration in 3- and 4-D Printing

2021 ◽  
pp. 294-347
Keyword(s):  
Design Parameters ◽  
Layer By Layer ◽  
Human Engineering ◽  
Functional Surface ◽  
Design Rules ◽  
Surface Design ◽  
Operation Conditions ◽  
Subsurface Material ◽  
Subsurface Layers ◽  
Successful Design

This chapter explores the potential of bio-inspiration in 3- and 4-D printing. The authors argue that the true potential of texturing hasn't been realized yet not because of the lack of enabling texturing technologies but because of the severe lack of detailed information about the functional details of texturing in a tribological situation, that is, how surface features, their geometry, interact with the functional gradients present within the subsurface layers to control the friction profile of a structure. The material emphasizes the potential of bio-inspired surfaces in providing a pathway for realizing true synchronization of function through a layer-by-layer customization of surface and subsurface material. In particular the chapter discusses methodologies to extract design parameters that lead to manifesting 4-D printed tribological constructs where surface and sub-surfaces respond optimally to external stimulants represented by the operation conditions of load, speed, and ambient temperature. Successful design of functional deterministic surfaces is not a product of mere biomimicry. Rather, it culminates probing the geometry, texture, form, and construction of the bio-analogue and linking these ingredients to the desired functional profile of the surface in the human engineering domain, that is, generation of bio-inspired functional surface designs stems from implementing design rules rather than replication of natural constructions. Deduction of design rules requires decoding the metrological features and the analysis of surface performance, of bio-analogues using standardized engineering methods. Success in designing a bio-inspired surface, therefore, requires a trans-disciplinary approach that combines engineering, physics, and biology. These don't combine naturally since they entail different methodologies of problem solving and investigations. It is hoped that this book would bridge the gap between the disciplines in the context of biomimetic surface design and construction. Further, it is hoped that the material would equip the reader with the basic skills needed to navigate between the biological and the engineering domains.

scholarly journals Misalignment in Gas Foil Journal Bearings: An Experimental Study

2008 ◽  
Author(s):  
Samuel A. Howard
Keyword(s):  
Journal Bearings ◽  
System Level ◽  
Design Parameters ◽  
Foil Bearing ◽  
Alignment System ◽  
Successful Design ◽  
Shaft Alignment ◽  
Bearing Force ◽  
Management Schemes ◽  
Level Performance

As gas foil journal bearings become more prevalent in production machines, such as small gas turbine propulsion systems and microturbines, system level performance issues must be identified and quantified in order to provide for successful design practices. Several examples of system level design parameters that are not fully understood in foil bearing systems are thermal management schemes, alignment requirements, balance requirements, thrust load balancing, and others. In order to address some of these deficiencies and begin to develop guidelines, this paper presents a preliminary experimental investigation of the misalignment tolerance of gas foil journal bearing systems. Using a notional gas foil bearing supported rotor and a laser-based shaft alignment system, increasing levels of misalignment are imparted to the bearing supports while monitoring temperature at the bearing edges. The amount of misalignment that induces bearing failure is identified and compared to other conventional bearing types such as cylindrical roller bearings and angular contact ball bearings. Additionally, the dynamic response of the rotor indicates that the gas foil bearing force coefficients may be affected by misalignment.

scholarly journals Misalignment in Gas Foil Journal Bearings: An Experimental Study

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Samuel A. Howard
Keyword(s):  
Journal Bearings ◽  
System Level ◽  
Design Parameters ◽  
Foil Bearing ◽  
Alignment System ◽  
Successful Design ◽  
Shaft Alignment ◽  
Bearing Force ◽  
Management Schemes ◽  
Level Performance

As gas foil journal bearings become more prevalent in production machines, such as small gas turbine propulsion systems and microturbines, system level performance issues must be identified and quantified in order to provide for successful design practices. Several examples of system level design parameters that are not fully understood in foil bearing systems are thermal management schemes, alignment requirements, balance requirements, thrust load balancing, and others. In order to address some of these deficiencies and begin to develop guidelines, this paper presents a preliminary experimental investigation of the misalignment tolerance of gas foil journal bearing systems. Using a notional gas foil bearing supported rotor and a laser-based shaft alignment system, increasing levels of misalignment are imparted to the bearing supports while monitoring temperature at the bearing edges. The amount of misalignment that induces bearing failure is identified and compared with other conventional bearing types such as cylindrical roller bearings and angular contact ball bearings. Additionally, the dynamic response of the rotor indicates that the gas foil bearing force coefficients may be affected by misalignment.

The Effect of a Fractal Profile Tolerance on the Dynamic Performance of Cams

1996 ◽  
Author(s):  
Daniel A. McAdams ◽  
Kristin L. Wood
Keyword(s):  
Fractal Geometry ◽  
Surface Characterization ◽  
Dynamic Performance ◽  
Design Parameters ◽  
Fractal Surface ◽  
Profile Error ◽  
Dynamic Simulations ◽  
Profile Tolerance ◽  
Cam Follower ◽  
Successful Design

Abstract To ensure a successful design, it is important to understand the effect that design parameters have on design performance. Tolerances are an important subset of design parameters. In this paper, the relevance of fractal surface characterization for profile tolerances is investigated. The notion of fractal geometry is discussed. The validity of a fractal characterization on a cam surface is determined. Dynamic simulations of a cam-follower system are used to qualify the effect of a fractal profile error on system performance.

Analysis of Mechanical Properties of Wood Dust Reinforced Epoxy Composite Using Response Surface Methodology

2015 ◽  
Vol 1119 ◽  
pp. 258-262
Author(s):  
Rahul Kumar ◽  
Kaushik Kumar ◽  
Sumit Bhowmik
Keyword(s):  
Response Surface ◽  
Filler Content ◽  
Epoxy Composite ◽  
Design Parameters ◽  
Wood Dust ◽  
Flexural Stress ◽  
Surface Design ◽  
Two Factors ◽  
Flexural Tests ◽  
Central Composite

In this paper, the sundi wood dust reinforced epoxy composite is developed with three different filler content. The tensile and flexural tests are performed at three different speeds to study the mechanical behavior of the composites. Experiments are conducted based on central composite design considering two factors viz. speed and filler content. The experimental data are statistically analyzed by using analysis of variance to find out the significant parameters. Response surface design has been employed to determine optimum design parameters. It has been observed from the analysis that speed is the main significant factor affecting the load and tensile stress values but for flexural stress, filler content is the main significant factor at 95% confidence level.

Modeling of PVA Modified Non-Woven for Submerged Membrane Bioreactor Treating Synthetic Wastewater

2011 ◽  
Vol 356-360 ◽  
pp. 1109-1117
Author(s):  
Chun Hua Zhang ◽  
Yu Ying Dong ◽  
Feng Jie Zhang
Keyword(s):  
Wastewater Treatment ◽  
Relative Error ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Design Parameters ◽  
Stable Operation ◽  
Fouling Resistance ◽  
Submerged Membrane Bioreactor ◽  
Operation Conditions ◽  
The Relationship

In this study, a mathematical model has been developed for the submerged membrane bioreactor (SMBR). Polyvinyl alcohol (PVA) Modified Non-woven model is immerged in MBR to be used for synthetic wastewater treatment. The results show that membrane fouling resistance is mostly cake resistance occurring during filtration. Based on the concept of specific fouling resistance and Darcy law that describes the relationship between flux and resistance during filtration driven by pressure, a module is established to explain the relationship between specific fouling resistance and time during filtration controlled by cake resistance in SMBR. The decline trend of flux can be predicted by the model. The model is used to predict the decline trend of flux during pharmaceutical wastewater treatment. Compared with experimental data, the relative error is less than 10% at t>b, the relative error is less than 5% at t>2b. It shows that the model can predict the decline trend of flux during stable operation of SMBR. But the relative error is bigger during unstable operation at initial stage (t<b). The model developed in this study would provide a useful tool in optimizing operation conditions as well as design parameters for a SMBR system.

Modeling Approach for the Electrodynamics of Multilayer DE Stack-Transducers

2016 ◽  
Author(s):  
Thorben Hoffstadt ◽  
Philip Meier ◽  
Jürgen Maas
Keyword(s):  
Spatial Distribution ◽  
Field Distribution ◽  
Electrical Network ◽  
Design Parameters ◽  
Electrical Behavior ◽  
Electrical Parameters ◽  
Static Behavior ◽  
Design Rules ◽  
Modeling Approach ◽  
Lumped Parameters

In most cases the electrical behavior of dielectric elastomer (DE) transducers is modeled by an equivalent circuit with lumped electrical parameters. Here, the capacitance is obtained under consideration of the active area of the whole DE transducer, while additional parallel and series resistances model the losses in the dielectric and the electrode respectively. Since this represents a quite simple modeling approach it is very common. However, in general a DE transducer has a certain spatial distribution depending on the design of the considered transducer. Thus, a model with lumped parameters might be inaccurate and does not take into account the field-distribution within the DE transducer. Since no analytical expression of the field-distribution can be derived by solving the partial differential equations for diagonal-edge contacts, within this contribution an electrical network model for a multilayer DE stack-transducer is presented. This model takes into account the influence of the contacting of each single transducer film as well as the electrical interaction of these films and their spatial distribution. Based on this model the influence of different design parameters can be investigated, resulting in design rules for the considered transducers with both optimized transient and static behavior.

scholarly journals NUMERICAL MODELING AND EXPERIMENTAL RESEARCH OF A LIQUID-LIQUID EJECTORS WITH A CURVED INITIAL MIXING CHAMBER AREA AND WITH DIRECT MIXING CAMERA

2020 ◽  
pp. 88-95
Author(s):  
Salar Kartas ◽  
◽  
Vladimir Panchenko ◽  
Yury Aleksandrov ◽  
◽  
...  
Keyword(s):  
Pressure Drop ◽  
Experimental Studies ◽  
Design Parameters ◽  
Layer By Layer ◽  
Relative Pressure ◽  
Initial Portion ◽  
Ansys Fluent ◽  
Ejection Coefficient ◽  
Mixing Chamber ◽  
Calculation Results

The article presents the results of numerical simulations and experimental studies of a liquid-liquid ejector with a curved initial portion of the mixing chamber. The experiment was conducted on liquid-liquid ejectors, models of which are made on a 3D printer, by the method of layer-by-layer deposition. The influence of possible manufacturing errors of the ejector on its characteristics is estimated. The issues of the use of liquid ejectors designed to work in the field of various predetermined ejection coefficients are considered. The theoretical ejection coefficient and the reasons for reducing the ejection coefficient in real ejectors are determined. The obtained dependences make it possible to determine the optimal design parameters of a liquid ejector and thereby increase its ejection coefficient. The relative pressure drop is shown at a low coefficient and at a high ejection coefficient. The calculated and experimental results of determining the ejection coefficient for liquid ejectors, which are widely used in various fields of technology, are presented. The results of numerical simulation of internal processes in the ANSYS-Fluent hydro-gasdynamic application package flowing in a single-phase liquidliquid ejector based on the study of a small-sized model are presented. As a result of the simulation, a good agreement was obtained between the calculation results of the model corresponding to the real prototype and the experimental data and comparison with the results of other authors. Several conclusions can be drawn from the results of the study. For example, a region of values of the ejection coefficient was found in which the relative pressure drop created by the ejector increases with an increase in the ejection coefficient.

scholarly journals Design approaches for additive manufactured components, with a focus on selective laser melting

2017 ◽  
Vol 50 (3) ◽  
pp. 279-282
Author(s):  
Erin Komi ◽  
Petteri Kokkonen
Keyword(s):  
Selective Laser Melting ◽  
3D Model ◽  
Layer By Layer ◽  
Model Data ◽  
Laser Melting ◽  
Component Design ◽  
Subtractive Manufacturing ◽  
Successful Design ◽  
Manufacturing Techniques ◽  
And Performance

Additive manufacturing (AM) of metal components is characterized by the joining of material particles or feedstock to make parts described by 3D model data in typically a layer by layer fashion [1]. These modern and constantly improving manufacturing techniques inherently allow far more geometric freedom than traditional “subtractive” manufacturing processes, and thus necessitate novel approaches to component design. Careful utilization of this geometric freedom can be translated into products characterized by improved functionality and performance, simplified assemblies, are customizable, and/or lightweight [2-5]. This paper provides a brief overview design approaches, manufacturing limitations, and available tools for successful design of additive manufactured components, with special attention paid to the selective laser melting (SLM) approach.

scholarly journals Studying Kinematics and Capacity of Tools of Organic Fertilizer Loader

2018 ◽  
Vol 7 (4.38) ◽  
pp. 1109
Author(s):  
Evgeny Evgenievich Demin ◽  
Pavel Ivanovich Pavlov ◽  
Rustam Rafitovich Khakimzyanov ◽  
Victor Alekseevich Mukhio ◽  
Andrey Anatolyevich Protasov
Keyword(s):  
Physicochemical Properties ◽  
Kinematic Analysis ◽  
Organic Fertilizer ◽  
Theoretical Background ◽  
Organic Fertilizers ◽  
Design Parameters ◽  
Loading Capacity ◽  
Operation Conditions ◽  
Load Handling ◽  
Tool Diameter

This article discusses the issue of theoretical background of capacity of new load handling tools of continuous loaders for organic fertilizers on the basis of kinematic analysis of their motion. Loader efficiency is estimated by a set of performances the main of which is loading capacity. The loading capacity is determined by design and kinematic parameters of tools. Theoretical determination of capacity is an important scientific task, its solution would permit to substantiate loader parameters for predetermined operation conditions. Kinematic analysis of spiral, vane, shredding screw load handling tools is performed. Capacity of shredding tools is determined as a function of design and operation parameters as well as physicochemical properties of organic fertilizers. The obtained equations take into account motion pattern of tools, kinematic and design parameters as well as physicochemical properties of manure. The capacity depends quadratically on tool diameter. Dependence on other parameters is in fact directly proportional. The influence of tool angular velocity and its forward velocity is related with trigonometric functions of rotation angles during separation and gripping of organic fertilizers.  

scholarly journals A review on integration of lightweight gradient lattice structures in additive manufacturing parts

2020 ◽  
Vol 12 (6) ◽  
pp. 168781402091695
Author(s):  
Asliah Seharing ◽  
Abdul Hadi Azman ◽  
Shahrum Abdullah
Keyword(s):  
Additive Manufacturing ◽  
Weight Ratio ◽  
Design Parameters ◽  
Layer By Layer ◽  
Lattice Structures ◽  
Unit Cells ◽  
Metallic Additive ◽  
Manufacturing Techniques ◽  
Future Work ◽  
Design Freedom

This review analyses the design, mechanical behaviors, manufacturability, and application of gradient lattice structures manufactured via metallic additive manufacturing technology. By varying the design parameters such as cell size, strut length, and strut diameter of the unit cells in lattice structures, a gradient property is obtained to achieve different levels of functionalities and optimize strength-to-weight ratio characteristics. Gradient lattice structures offer variable densification and porosities; and can combine more than one type of unit cells with different topologies which results in different performances in mechanical behavior layer-by-layer compared to non-gradient lattice structures. Additive manufacturing techniques are capable of manufacturing complex lightweight parts such as uniform and gradient lattice structures and hence offer design freedom for engineers. Despite these advantages, additive manufacturing has its own unique drawbacks in manufacturing lattice structures. The rules and strategies in overcoming the constraints are discussed and recommendations for future work were proposed.

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