Computing Marginal Cost of Durability of Energy Systems Components by Structural Optimization with Fatigue Constraints

2021 ◽  
pp. 1-26
Author(s):  
Felipe Meneguzzo Pasquali ◽  
John Hall
Keyword(s):  
Marginal Cost ◽  
Computational Models ◽  
Formal Method ◽  
Energy Systems ◽  
Design Parameters ◽  
Bottom Line ◽  
Sustainable Living ◽  
Design Life ◽  
System Life ◽  
Fatigue Constraints

Abstract There is a relationship between product durability and the effect the product has on the environment and economy. One approach that impacts this dynamic involves a circular economy, which is gaining traction as businesses shift towards a product as a service model. One example of this is emerging in the energy sector. Given this shift, the life of the product becomes important as it impacts the bottom line of the business. This gives rise to the Marginal Cost of Durability (MCD) metric. The MCD relates the product cost to the system life. System life is particularly important for renewable energy systems that promote sustainable living. These large structures require materials and end-of-life disposal. Design requirements for material also increase as the design life increases. Additional materials safeguard against failure such as fatigue. Currently, there is no formal method for determining the MCD. This paper examines a method for measuring MCD for the commercial class of wind energy systems. A metamodel of the damage response is built instead of expensive computational models. Design optimization is used to find design parameters using fatigue damage as a constraint. This process is repeated for a set of system life values, yielding a set of designs. A mathematical relationship between life and cost is found. An example of this method is applied to the study of wind turbine tower life. The results from the proposed method provide information that is used to determine the design life of a system.

Optimising Foundation Skirt Geometries for Reliable Foundation Capacity and Installation

2017 ◽  
Author(s):  
M. F. Bransby ◽  
D. O’Driscoll ◽  
H. Zhu ◽  
M. F. Randolph ◽  
T. Drummen
Keyword(s):  
Marginal Cost ◽  
Efficient Solution ◽  
Cost Effective ◽  
The Self ◽  
Significant Cost ◽  
Design Life ◽  
Parametric Studies ◽  
Foundation Type ◽  
Fabrication Costs ◽  
Installation Time

Increasing numbers of subsea structures related to wells and pipelines are being placed on the seabed as part of typical subsea or tie-back developments. Given the proliferation of these structures and the marginal cost of offshore developments, controlling installation and fabrication costs for subsea structures can be key to project viability. Skirted mudmats are often the most cost-effective foundation type, and particular additional design focuses on optimising their cost by minimising foundation weight and installation time. Subsea foundations must be designed to withstand all applied loads during their design life (e.g. during set-down, tie-in, hydrotest, operation etc.) with suitable reliability. Using skirts, peripheral or internal, to improve the sliding resistance is an efficient solution provided the self-weight of the subsea structure on set-down is sufficiently large to ensure installation of the skirts (even for the strongest likely seabed conditions), but can lead to significant cost increases if additional ballast is required to ensure this. The paper examines how foundation skirt geometries can be optimised in order to provide sufficient foundation in-place capacity whilst minimising the amount of self-weight required for their installation. Parametric studies are presented that show how the sliding capacity of individual skirts is affected by the weight of the structure, and also the spacing and position within the foundation plan.

scholarly journals Modified Multi Input Multilevel DC-DC Boost Converter for Hybrid Energy Systems

2020 ◽  
Vol 9 (4) ◽  
pp. 1067-1072
Keyword(s):  
Output Voltage ◽  
Low Voltage ◽  
Complex Structure ◽  
Energy Systems ◽  
Input Voltage ◽  
Boost Converter ◽  
Design Parameters ◽  
Hybrid Energy ◽  
Hybrid Energy Systems ◽  
Constant Output

DC-DC converters are playing an important role in designing of Electric Vehicles, integration of solar cells and other DC applications. Contemporary high power applications use multilevel converters that have multi stage outputs for integrating low voltage sources. Conventional DC-DC converters use single source and have complex structure while using for Hybrid Energy Systems. This paper proposes a multi-input, multi-output DC-DC converter to produce constant output voltage at different input voltage conditions. This topology is best suitable for hybrid power systems where the output voltage is variable due to environmental conditions. It reduces the requirement of magnetic components in the circuit and also reduces the switching losses. The proposed topology has two parts namely multi-input boost converter and level-balancing circuit. Boost converter increases the input voltage and Level Balancing Circuit produce Multi output. Equal values of capacitors are used in Level Balancing Circuit to ensure the constant output voltage at all output stages. The operating modes of each part are given and the design parameters of each part are calculated. Performance of the proposed topology is verified using MATLAB/Simulink simulation which shows the correctness of the analytical approach. Hardware is also presented to evaluate the simulation results.

Generation of Complex Energy Systems by Combination of Elementary Processes

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
A. Toffolo ◽  
S. Rech ◽  
A. Lazzaretto
Keyword(s):  
Design Optimization ◽  
Ad Hoc ◽  
Energy Systems ◽  
Optimization Procedure ◽  
Thermodynamic Cycle ◽  
Energy System ◽  
Design Parameters ◽  
System Configuration ◽  
Complex Energy ◽  
Synthesis Design

The fundamental challenge in the synthesis/design optimization of energy systems is the definition of system configuration and design parameters. The traditional way to operate is to follow the previous experience, starting from the existing design solutions. A more advanced strategy consists in the preliminary identification of a superstructure that should include all the possible solutions to the synthesis/design optimization problem and in the selection of the system configuration starting from this superstructure through a design parameter optimization. This top–down approach cannot guarantee that all possible configurations could be predicted in advance and that all the configurations derived from the superstructure are feasible. To solve the general problem of the synthesis/design of complex energy systems, a new bottom–up methodology has been recently proposed by the authors, based on the original idea that the fundamental nucleus in the construction of any energy system configuration is the elementary thermodynamic cycle, composed only by the compression, heat transfer with hot and cold sources and expansion processes. So, any configuration can be built by generating, according to a rigorous set of rules, all the combinations of the elementary thermodynamic cycles operated by different working fluids that can be identified within the system, and selecting the best resulting configuration through an optimization procedure. In this paper, the main concepts and features of the methodology are deeply investigated to show, through different applications, how an artificial intelligence can generate system configurations of various complexity using preset logical rules without any “ad hoc” expertise.

Quantification of Classical Gestalt Principles in Two-Dimensional Product Representations

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
José E. Lugo ◽  
James P. Schmiedeler ◽  
Stephen M. Batill ◽  
Laura Carlson
Keyword(s):  
Product Design ◽  
Design Process ◽  
Formal Method ◽  
Visual Design ◽  
Design Parameters ◽  
Two Dimensional ◽  
Mathematical Functions ◽  
Gestalt Principles ◽  
Visual Appearance

Gestalt principles have previously served as qualitative guidelines for good visual design in art, architecture, and product design. This paper introduces a formal method to quantify classical Gestalt principles (proximity, continuity, closure, symmetry, parallelism, and similarity) for two-dimensional product representations. With the approach, designers use their judgment to divide a 2D representation of a new concept or existing design into its key atomistic elements, identify the most appropriate Gestalt principles that apply to the grouping of those elements, and then can objectively quantify the design’s adherence to those principles using mathematical functions of the design parameters. This quantification provides a tool to augment a design team’s own subjective interpretations in evaluating and communicating a product’s visual appearance at any stage of or throughout the design process.

Probabilistic Multibody Modeling of Gearboxes for Wind Turbines

2011 ◽  
Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Loading ◽  
Design Parameters ◽  
Probabilistic Design ◽  
Deterministic Approach ◽  
Early Failure ◽  
Multibody Modeling ◽  
Design Life ◽  
Multibody Dynamic

Gearboxes have been prone to early failure rather than any mechanical part of modern wind turbines, much earlier than their predicted design life. Some studies indicated that gearboxes of wind turbines fail during the first 3 to 5 years of operation of the system as opposed to the total design life of the wind turbine, which usually is 20 years. Consequently, such failures cause the highest down time and extremely expensive replacement activities. Gearboxes are subjected to torsional, bending and axial wind loads which are yet not fully defined. The uncertainty in loading conditions and system design parameters has brought about the importance of considering probabilistic design and modeling approach than the traditional deterministic approach. Accordingly, the motivation of this study is to improve the reliability of gearboxes for wind turbine applications. A probabilistic multibody dynamic modeling of the gearbox, that fully integrates uncertainties in wind loading and design parameters, is sought. This paper presents previous studies and finally proposes the above mentioned approach as a potential way of improving, in general, the reliability of wind energy and, in particular, the gearboxes in wind turbines.

Optimum Design of Tractor Clutch PTO Finger by Using Topology and Shape Optimization

2015 ◽  
Author(s):  
O. Dogan ◽  
F. Karpat ◽  
N. Kaya ◽  
C. Yuce ◽  
M. O. Genc ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Shape Optimization ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Agricultural Activities ◽  
Element Analysis ◽  
Design Life ◽  
Topology And Shape Optimization

Tractors are one of the most important agricultural machinery in the world. They provide agricultural activities in challenging conditions by using various agricultural machineries which are added on them. Therefore, there has been a rising demand for tractor use for agricultural activities. During the power transmission, tractor clutches are exposed to high static and cyclic loading directly. Thus, most of clutch parts fail before completing their design life which is under 106 cycles. Especially, because of the high stress, there are a number of fractures and breakages are observed around the pin area of the finger mechanisms. Due to these reasons, it is necessary to re-design these fingers by using modern optimization techniques and finite element analysis. This paper presents an approach for analysis and re-designs process of tractor clutch PTO finger. Firstly, the original designs of the PTO fingers are analyzed by using finite element analysis. Static structural analyses are applied on these fingers by using ANSYS static structural module. The boundary conditions are determined according to the data from the axial fatigue test bench. Afterwards, the stress-life based fatigue analyses are performed with respect to Goodman criterion. It is seem that the original design of the PTO finger, failed before the design life. Hence, the PTO finger is completely re-designed by using topology and shape optimization methods. Topology optimization is used to find the optimum material distribution of the PTO fingers. Topology optimization is performed in solidThinking Inspire software. The precise dimensions of the PTO fingers are determined by using shape optimization and response surface methodology. Two different design parameters, which are finger thickness and height, are selected for design of experiment and 15 various cases are analyzed. By using DOE method three different equations are obtained which are maximum stresses, mass, and displacement depending on the selected design parameters. These equations are used in the optimization as objective and constraint equations in MATLAB. The results indicate that the proposed models predict the responses adequately within the limits of the parameters being used. The final dimensions of the fingers are determined after shape optimization. The new designs of the PTO fingers are re-analyzed in terms of static and fatigue analysis. The new design of the PTO finger passed the analysis successfully. As a result of the study, the finger mass is increased 7% but it is quite small. Maximum Equivalent Von-Misses stress reduction of 25.3% is achieved. Fatigue durability of the PTO finger is improved 53.2%. The rigidity is improved up to 27.9% compared to the initial design. The optimal results show that the developed method can be used to design a durable, low manufacturing cost and lightweight clutch parts.

Decision-Based Design Method for Computing Marginal Cost of Durability

2020 ◽  
Author(s):  
Felipe M. Pasquali ◽  
Jonatan Meza ◽  
John F. Hall
Keyword(s):  
Wind Turbine ◽  
Marginal Cost ◽  
Business Models ◽  
Formal Method ◽  
Design Method ◽  
New Paradigm ◽  
Wind Turbine Tower ◽  
The Cost ◽  
Decision Based Design ◽  
Product Durability

Abstract Product durability impacts both the environment and the economy. Companies are changing their business models to the circular economy. In this model, the ownership of the product remains with the manufacturer. With this new paradigm, determining the life of the product becomes even more important for the success of the business model. The metric defined as the Marginal Cost of Durability (MCD) determines the cost to increase or decrease the life of the system. For a system to last longer, more materials are needed to counteract the fatigue damage. While this metric has been defined and used in studies throughout the literature, there is a need for a formal method of collecting this data. This paper presents a novel method for measuring the MCD aided by Metamodel-Based Optimization. A case study is presented to demonstrate this method when applied to a wind turbine tower. The results indicate that there is an increasing linear relationship between life and cost. A wind turbine tower designed for 80 years has 34% more mass and cost than a 20-year design.

scholarly journals Weibull-Based Design Methodology for Rotating Structures in Aircraft Engines

2003 ◽  
Vol 9 (5) ◽  
pp. 313-325 ◽  
Author(s):  
Erwin V. Zaretsky ◽  
Robert C. Hendricks ◽  
Sherry Soditus
Keyword(s):  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Life Distribution ◽  
Disk System ◽  
Probability Of Survival ◽  
Design Life ◽  
Blade System ◽  
System Life ◽  
The Individual ◽  
Engine Maintenance

The NASA Energy-Efficient Engine (E3-Engine) is used as the basis of a Weibull-based life and reliability analysis. Each component's life, and thus the engine's life, is defined by high-cycle fatigue or low-cycle fatigue. Knowing the cumulative life distribution of each of the components making up the engine as represented by a Weibull slope is a prerequisite to predicting the life and reliability of the entire engine. As the engine's Weibull slope increases, the predicted life decreases. The predicted engine livesL5(95% probability of survival) of approximately 17,000 and 32,000 hr do correlate with current engine-maintenance practices without and with refurbishment, respectively. The individual high-pressure turbine (HPT) blade lives necessary to obtain a blade system lifeL0.1(99.9% probability of survival) of 9000 hr for Weibull slopes of 3, 6, and 9 are 47,391; 20,652; and 15,658 hr, respectively. For a design life of the HPT disks having probable points of failure equal to or greater than 36,000 hr at a probability of survival of 99.9%, the predicted disk system lifeL0.1can vary from 9408 to 24,911 hr.

scholarly journals Optimization of an Endoscopic Radiofrequency Ablation Electrode

2018 ◽  
Vol 12 (3) ◽  
Author(s):  
Bradley Hanks ◽  
Mary Frecker ◽  
Matthew Moyer
Keyword(s):  
Radiofrequency Ablation ◽  
Thermal Ablation ◽  
Computational Models ◽  
Optimization Procedure ◽  
Pancreatic Tissue ◽  
Design Parameters ◽  
Electrode Design ◽  
Systematic Design ◽  
Spherical Tumor ◽  
Compliant Electrode

Radiofrequency ablation (RFA) is an increasingly used, minimally invasive, cancer treatment modality for patients who are unwilling or unable to undergo a major resective surgery. There is a need for RFA electrodes that generate thermal ablation zones that closely match the geometry of typical tumors, especially for endoscopic ultrasound-guided (EUS) RFA. In this paper, the procedure for optimization of an RFA electrode is presented. First, a novel compliant electrode design is proposed. Next, a thermal ablation model is developed to predict the ablation zone produced by an RFA electrode in biological tissue. Then, a multi-objective genetic algorithm is used to optimize two cases of the electrode geometry to match the region of destructed tissue to a spherical tumor of a specified diameter. This optimization procedure is then applied to EUS-RFA ablation of pancreatic tissue. For a target 2.5 cm spherical tumor, the optimal design parameters of the compliant electrode design are found for two cases. Cases 1 and 2 optimal solutions filled 70.9% and 87.0% of the target volume as compared to only 25.1% for a standard straight electrode. The results of the optimization demonstrate how computational models combined with optimization can be used for systematic design of ablation electrodes. The optimization procedure may be applied to RFA of various tissue types for systematic design of electrodes for a specific target shape.

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