Academic literature on the topic 'Plastic foams industry Case studies'
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Journal articles on the topic "Plastic foams industry Case studies"
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Cinelli, Patrizia, Maurizia Seggiani, Maria Beatrice Coltelli, Serena Danti, Maria Cristina Righetti, Vito Gigante, Marco Sandroni, Francesca Signori, and Andrea Lazzeri. "Overview of Agro-Food Waste and By-Products Valorization for Polymer Synthesis and Modification for Bio-Composite Production." Proceedings 69, no. 1 (November 5, 2020): 22. http://dx.doi.org/10.3390/cgpm2020-07211.
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The increase in the world’s economic growth and global population requires a more efficient management of the Earth’s natural resources. The combined plastic and food sector forms an important part of the EU economy, accounting for 15 million jobs. Unlocking the innovation potential in the field of packaging and cosmetics will significantly contribute to job creation and competitiveness. Sustainable synthesis of polyhydroxyalkanaotes from agro-food by-products as well as synthesis of lactic acid co-polymers constitute a pathway to achieving sustainable polymeric matrices. Natural fibers, as well as polysaccharides (starch, cellulose, chitin, chitosan), cutin, and protein rich by-products, are abundantly available from the agro-food industry. Natural fibers may be modified chemically with enzymes or by treating their surface with natural waxes, with a significant improvement in adhesion and impact resistance. An overview on the availability, collection, treatment, and approach of valorization of largely available agro-food waste biomass for both polymer and biocomposite production is hereby reported, with examples of case studies and product developed in our research units, such as sustainable pots, rigid containers, active films, and non-woven tissue.
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Girginer Ozunlu, Burcu, and Fatma Seniha Guner. "An Industrial Case for Polypropylene Nanocomposite Foams: Lightweight, Soundproof Exterior Automotive Parts." Polymers 14, no. 6 (March 16, 2022): 1192. http://dx.doi.org/10.3390/polym14061192.
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Lightweighting is a challenge for the automotive industry, and foaming is a key technology used to address this problem. A new practical approach is studied to regulate the cell formation of copolymer polypropylene (co-PP) by utilizing graphene nanoplatelets (xGnP) as a process aid during foam injection molding. The approach was designed to enable process freedom to tune part performance by adjusting the amount of xGnP masterbatch. Two different levels of 1–2 wt % xGnP and 0.25–0.35 wt % supercritical fluid (SCF) were investigated. Prepared samples were compared with samples prepared by the traditional method (twin-screw extrusion followed by foam injection molding). The nanocomposite with 2 wt % xGnP comparatively showed about twofold reduction in cell size magnitude. Although the increment in SCF amount resulted in a 47% and 122% enhancement in flexural modulus and strength, respectively, and a 45% loss in Izod unnotched impact strength, the cell size was prone to increasing with regard to low melt strength as compared to neat foams. In conclusion, a 12% weight reduction fulfilled the desired performance parameters in terms of mechanical and sound insulation by utilizing 2 wt % xGnP as a process aid.
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Tudor, Valentina Constanta, Ancuta Marin, Diana Zamfir Vasca, Marius Mihai Micu, and Dragos Ion Smedescu. "The Influence of the Plastic Bags on the Environment." Materiale Plastice 55, no. 4 (December 30, 2018): 595–99. http://dx.doi.org/10.37358/mp.18.4.5081.
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It is known, as well as a rule, that plastic materials can not instictively and naturally degrade when released into the environment. Due to the persistence of plastics to degradation and also to propagation in industry, the problem of plastic pollution has progressed considerable in order to become a threat to global ecology, on land and sea. The present study presents a global mapping of actions brought in to reduce the use of plastic, plastic bags and foamed plastic products, followed by selected case studies from each region of the world, with more attention offered to the European Union countries and the strategies elaborated by them to provide a cleaner and safer environment.
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Ignat, Gabriela, Cintia Colibaba, Carmen Luiza Costuleanu, Ioan Moraru, Catalin Razvan Vintu, George Ungureanu, and Costica Bejinariu. "Studies Regarding the Efficiency of Grape Tannins Greening Plastics." Materiale Plastice 54, no. 3 (September 30, 2017): 586–88. http://dx.doi.org/10.37358/mp.17.3.4902.
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Grape marc, also known as grape pomace, is one of the most investigated bio-wastes derived mainly from grape skin and seeds, which is produced as a by-product of winemaking on the million-ton scale annually. Presently, the most important high-value use of grape pomace is in the production of oenological tannins, widely-used additives in the food and beverage industry. This article studies the possible use of grape waste in the plastic industry, as request of the consumer for green plastics with regards to environmental impact, and in the case of packaging, to improve the shelf-life and safety of the products contained. 4 white grape varieties and 4 red grape varieties (most cultivated grape varieties in Romania) were taken into study, processed using different technological methods and the spent material (grape skins and seeds) were analysed regarding their total phenolic compounds and total tannins.
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Slišković, Merica, Helena Ukić Boljat, Igor Jelaska, and Gorana Jelić Mrčelić. "Review of Generated Waste from Cruisers: Dubrovnik, Split, and Zadar Port Case Studies." Resources 7, no. 4 (November 9, 2018): 72. http://dx.doi.org/10.3390/resources7040072.
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The amount of waste generated is becoming an increasing problem both in terms of inefficient use of resources and its harmful effects. Large quantities of waste originate from land, but a certain amount of waste is generated at sea, in which shipping holds its share. A recent analysis for 2015–2016 has rated the Croatian ports of Dubrovnik, Split, and Zadar in the top 10 out of 20 main cruising ports in the Adriatic Sea. As it is clear that a large number of persons present onboard generate a large amount of waste, the aim of this paper is to estimate the amount of waste (plastic, domestic, and food) and examine the significance of its increasing quantity produced by cruisers in the three main cruiser ports in the Croatian part of the Adriatic Sea for the period 2014–2017. Cruise calls correlation, together with repeated measures one-way Analysis of variance -ANOVA, showed that a future increase in the port calls for Zadar can be expected while, for the port of Dubrovnik, a decrease is projected, which is in correspondence with the taken measures for a reduction in the adverse effects of the cruise industry. Regarding the type of waste, domestic waste contributes the most with 62%, followed by the plastic waste with 26%, and food waste, which makes only 11% of the total amount of waste for that year. Waste minimization practices and further recommendations for the improvement of waste management practices are presented and put into relation with specific measures to protect and preserve the quality of the environment.
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Salhofer, Stefan, Aleksander Jandric, Souphaphone Soudachanh, Thinh Le Xuan, and Trinh Dinh Tran. "Plastic Recycling Practices in Vietnam and Related Hazards for Health and the Environment." International Journal of Environmental Research and Public Health 18, no. 8 (April 15, 2021): 4203. http://dx.doi.org/10.3390/ijerph18084203.
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Waste plastic today is a global threat. The rapid increase in global production and use has led to increasing quantities of plastics in industrial and municipal waste streams. While in industrialized countries plastic waste is taken up by a waste management system and at least partly recycled, in low-income countries adequate infrastructure to collect and treat waste adequately is often not in place. This paper analyzes how plastic waste is handled in Vietnam, a country with a fast-growing industry and growing consumption. The recycling of plastic waste typically takes place in an informal context. To demonstrate this in more detail, two rural settlements—so-called craft villages—are taken as case studies. Technologies and processes for plastic recycling are described and related risks for human health and the environment are shown, as well as the potential for the improvement of this situation.
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Onawole, Abdulmujeeb T., Ibnelwaleed A. Hussein, Mohammed A. Saad, Nadhem Ismail, Ali Alshami, and Mustafa S. Nasser. "Theoretical Studies of a Silica Functionalized Acrylamide for Calcium Scale Inhibition." Polymers 14, no. 12 (June 9, 2022): 2333. http://dx.doi.org/10.3390/polym14122333.
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The calcium carbonate (CaCO3) scale is one of the most common oilfield scales and oil and gas production bane. CaCO3 scale can lead to a sudden halt in production or, worst-case scenario, accidents; therefore, CaCO3 scale formation prevention is essential for the oil and gas industry. Scale inhibitors are chemicals that can mitigate this problem. We used two popular theoretical techniques in this study: Density Functional Theory (DFT) and Ab Initio Molecular Dynamics (AIMD). The objective was to investigate the inhibitory abilities of mixed oligomers, specifically acrylamide functionalized silica (AM-Silica). DFT studies indicate that Ca2+ does not bind readily to acryl acid and acrylamide; however, it has a good binding affinity with PAM and Silica functionalized PAM. The highest binding affinity occurs in the silica region and not the –CONH functional groups. AIMD calculations corroborate the DFT studies, as observed from the MD trajectory that Ca2+ binds to PAM-Silica by forming bonds with silicon; however, Ca2+ initially forms a bond with silicon in the presence of water molecules. This bonding does not last long, and it subsequently bonds with the oxygen atoms present in the water molecule. PAM-Silica is a suitable calcium scale inhibitor because of its high binding affinity with Ca2+. Theoretical studies (DFT and AIMD) have provided atomic insights on how AM-Silica could be used as an efficient scale inhibitor.
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Chen, J. J., D. McCarty, D. Slack, and H. Rundle. "Full scale case studies of a simplified aerated filter (BAF) for organics and nitrogen removal." Water Science and Technology 41, no. 4-5 (February 1, 2000): 1–4. http://dx.doi.org/10.2166/wst.2000.0417.
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The limitation of available land for wastewater treatment facilities has challenged environmental engineers in searching for efficient and effective treatment systems that will minimize space requirements for waste treatment. To meet these requirements, a fixed film biological process using a DeepBedTM filter for aerobic and anoxic treatment was developed. The innovative biotechnology uses sand as the media to which microorganisms attach and as the filter media for solids retention. The unique characteristics of the biosystem combine long sludge age and short hydraulic detention time and provide small footprints for the bioreactor. The novel technology has been successfully practiced for industrial and municipal wastewater treatment in three (3) continents. This article gives details of a US facility to treat coke plant effluent with high ammonia and phenol content, describes a plant in Taiwan for polishing plastic manufacturing wastewater by combining ozone and biofiltration, illustrates nitrogen removal from a semiconductor factory in Korea, and shows the results of a municipal treatment plant in Britain using BAF to pretreat peak loads from the dairy industry.
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Danilenko, T. V., and I. R. Nasirov. "Production of motor benzene via plastic processing as perspective direction of "green" fuel power industry." Azerbaijan Oil Industry, no. 10 (October 15, 2020): 54–61. http://dx.doi.org/10.37474/0365-8554/2020-10-54-61.
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The paper reviews the topicality and practical significance of the implementation of processing technology of plastic with the purpose of obtaining raw material for manufacturing motor benzene. It is shown that this case is the advantageous strategy for the damage reduction to the environment from the oil-gas complex and usage of commercial gasoline based on the fossil hydrocarbon crude and for the utilization of plastic wastes as well. The perspective technologies of plastic processing including pyrolysis, catalytic cracking, hydrothermal liquefaction based on the bibliographic review and the recommendations on the improvement of benzene component obtained as a basis for industrial production of motor benzene are presented. In the capacity of the last ones, the implementation of alcohol mixed octane-increasing additives based on the ethanol is justified. It is shown that using alcohol not only increases octane number of the fuel, but also saves expensive hydrocarbon components, allows reducing the toxic high-octane aromatic hydrocarbons in the gasoline, improves the distribution of octane numbers by benzene fractions based on the reformat, as well as expands the crude base for fuel production due to the non-oil raw. The studies showed that adding 10 % of alcohol is the optimum concentration, as on the one hand it provides the growth of knock characteristics and phase stability of the gasoline, on the other hand does not require additional regulation of motor engine for using such fuel.
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Ezeudu, Obiora B., and Tochukwu S. Ezeudu. "Implementation of Circular Economy Principles in Industrial Solid Waste Management: Case Studies from a Developing Economy (Nigeria)." Recycling 4, no. 4 (October 21, 2019): 42. http://dx.doi.org/10.3390/recycling4040042.
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The existing solid waste management principles are increasingly being replaced with discussions on circular economy (CE) principles in contemporary deliberations on solid waste handling. This shift is supported by the global adoption of the concept of sustainable development. The CE offers better prospects to solid waste management and has been implemented successfully in its full theory, practice, and policies in some developed locations of the world. The socio-economic disadvantages, insufficient expert knowledge and a lack of information have hindered its appropriateness and implementation in low and middle-income countries. Hence, the current research study examines the challenges and opportunities of implementing the circularity principle at the industrial sector level of a typical developing economy—Nigeria. Four different industries were selected for this case study—telecommunications, water packaging, pulp and paper and the food industry. These industries represent the major waste streams in an urban solid waste mix (waste electrical and electronic equipment (WEEE), plastic, paper and organic). This study discovered several barriers and existing pre-conditions in place that could either foster or militate against the smooth and successful application of a CE model as a simple modification of the generic model. This study also discussed future directions on the implementation of the model.
Dissertations / Theses on the topic "Plastic foams industry Case studies"
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Jamshidi, Somayeh. "Key drivers to start an e-commerce in B2B companies : Two case studies in the plastic industry." Thesis, Karlstads universitet, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-67868.
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Background: Internet, as everybody knows, has a lot of advantages and possibilities. One of these possibilities for companies is changing their business to electronic commerce (e-commerce). Almost all companies might need this type of business to sustain in future and compete with others. Most of the traditional businesses decide to change their business to e-commerce to have more profits in the future. However, this kind of commercial (e-commerce) may have its own risks and difficulties. Therefore, financial drivers can help companies to start or change previous business to e-commerce better and more easily. Purpose: The aim of this study is to demonstrate the importance of financial drivers for business to business (B2B) companies when they are starting an e-commerce. Since financial drivers might motivate the companies to start with e-commerce. Design/Methodology/Approach: A qualitative method and two case studies in the plastic industry are used. There are six interviews with a company named Alpha and two with a company named Beta. The researcher chooses the semi-structured interview for this study. The data are collected from mentioned interviews and secondary data. Findings: The finding of this study is divided into two parts. A) The necessity of companies to start an e-commerce, B) The importance of the financial drivers for B2B companies. This study shows that the financial driver has a significant effect to start an e-commerce. The advantages of selling products through e-commerce are as follows: increasing sales and revenues, decreasing transaction costs, improving liquidity problems, introducing the company brand and reaching products in 24/7. Practical implications: The result of this study has several implications for B2B companies such as management motivation to start an e-commerce. This study introduces financial drivers as an important key to motivate management to start with e-commerce.
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Kwan, Cheng Lai-man Heidi, and 關鄭麗敏. "Recycling business in Hong Kong: an economic and environmental perspective." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31252643.
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Chen, Chia-Ya, and 陳嘉堯. "The Development of Virtual Factory Operation Models in Manufacturing Industry --- Case Studies of IC Foundry, steel, and plastic Industry." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/70548580100658048357.
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碩士長榮管理學院
經營管理研究所
90
In the advent of the new economy under the Internet, this century would be the era characterized by the competition among the application of information, network and e-commerce. Under this new economy, enterprises could timely control production information through the virtual factory. This could contribute to the realization of the “most appropriate production strategy in the world”. The main objective of this study is to analyze the operation model of virtual factories, and to evaluate the factors that affect the development of the operation model of virtual factories in the manufacturing industry. In this study, by literature reviews, the operation model of virtual factories would be constructed in terms of enterprise resources planning（ERP）, supply chain management（SCM）,and customer relationship management（CRM）. This operation model of virtual factories would be served as the framework of analysis for the operations of the virtual factories in the IC foundry industry, steel industry and plastic industry, respectively. The findings on the virtual factory operations in there industries by applying the virtual factory framework in this study indicated that different industries have different point of emphasis in their own operation model of virtual factories because of different competitive environments. Finally, this study would propose some conclusions about the development of virtual factory operation models for the manufacturing industries.
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"Business review and strategic plan for a small plastic mould making shop in Hong Kong." 1994. http://library.cuhk.edu.hk/record=b5889447.
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by Ngan Chi-Cheung.Thesis (M.B.A.)--Chinese University of Hong Kong, 1994.
Includes bibliographical references (leaves 124-125).
ABSTRACT --- p.i
TABLE OF CONTENTS --- p.iii
ACKNOWLEDGEMENTS --- p.viii
CHAPTER
Chapter I. --- INTRODUCTION --- p.1
Chapter 1.1 --- Initiation of the Project --- p.1
Chapter 1.2 --- Objectives --- p.2
Chapter 1.3 --- Arrangement of the Report --- p.3
Chapter II. --- METHODOLOGY --- p.5
Chapter 2.1 --- Scope --- p.5
Chapter 2.2 --- Approaches --- p.5
Chapter 2.3 --- Studying Steps --- p.7
Chapter 2.3.1 --- Market Research --- p.7
Chapter 2.3.2 --- Financial Analysis --- p.8
Chapter 2.3.3 --- SWOT Analysis --- p.9
Chapter 2.3.4 --- Problems and Difficulties Identification --- p.9
Chapter 2.3.5 --- Strategic Plan Formulation --- p.9
Chapter III. --- PLASTIC MOULD MAKING INDUSTRY IN HONG KONG
Chapter 3.1 --- Product Profile --- p.11
Chapter 3.1.1 --- Product Range across the whole Mould Making Industry --- p.11
Chapter 3.1.2 --- Manufacturing Process --- p.12
Chapter 3.2 --- Market Profile --- p.13
Chapter 3.2.1 --- The Mould Market as a Whole --- p.13
Chapter 3.2.2 --- Plastic Mould Market Profile --- p.15
Chapter 3.3 --- Customer Profile --- p.16
Chapter 3.3.1 --- End-User Group --- p.16
Chapter 3.3.2 --- Customer Group --- p.17
Chapter 3.3.2 --- Domestic Customer Needs --- p.19
Chapter 3.4 --- Competitor Profile --- p.20
Chapter 3.4.1 --- Domestic Competition --- p.20
Chapter 3.4.2 --- Foreign Competition --- p.22
Chapter 3.5 --- Distribution Profile --- p.25
Chapter 3.5.1 --- Maintenance and Acquisition of Customers --- p.25
Chapter 3.5.2 --- Order Taking --- p.26
Chapter 3.6 --- Outlook of the Industry --- p.27
Chapter 3.6.1 --- Plastics Industry --- p.27
Chapter 3.6.2 --- Plastic Mould Making Industry --- p.29
Chapter IV. --- THE SMALL PLASTIC MOULD MAKING SHOP --- p.32
Chapter 4.1 --- Background of the Small Business --- p.32
Chapter 4.2 --- Company Profile of CL --- p.33
Chapter 4.2.1 --- Organization Structure --- p.33
Chapter 4.2.2 --- Management --- p.34
Chapter 4.2.3 --- Assets --- p.36
Chapter 4.2.4 --- Staffing --- p.37
Chapter 4.3 --- Product Profile of CL --- p.40
Chapter 4.4 --- Customer Profile of CL --- p.41
Chapter 4.5 --- Competitor Profile of CL --- p.42
Chapter V. --- PROBLEM IDENTIFICATION FOR CL --- p.44
Chapter 5.1 --- Financial Analysis --- p.44
Chapter 5.1.1 --- Simplifications and Assumptions --- p.44
Chapter 5.1.2 --- Cash Flow Statements --- p.46
Chapter 5.1.3 --- Income Statements --- p.49
Chapter 5.1.4 --- Retained Earnings Statements and Balance Sheets --- p.50
Chapter 5.1.5 --- Ratio Analysis --- p.51
Chapter 5.1.6 --- Comparison with Industrial Financial Data --- p.54
Chapter 5.2 --- SWOT Analysis --- p.56
Chapter 5.2.1 --- Strengths --- p.56
Chapter 5.2.2 --- Weaknesses --- p.59
Chapter 5.2.3 --- Opportunities --- p.63
Chapter 5.2.4 --- Threats --- p.67
Chapter VI. --- STRATEGIC PLAN FOR CL --- p.71
Chapter 6.1 --- An overview of CL --- p.71
Chapter 6.2 --- Future Growth of CL --- p.73
Chapter 6.3 --- Business Objectives --- p.74
Chapter 6.4 --- Strategic Plan --- p.74
Chapter 6.4.1 --- Financial Strategies --- p.76
Chapter 6.4.2 --- Management Strategies --- p.79
Chapter 6.4.3 --- Product Strategies --- p.85
Chapter 6.4.4 --- Production Strategies --- p.86
Chapter 6.4.5 --- Marketing Strategies --- p.88
Chapter 6.4.6 --- Implementation Schedule --- p.90
Chapter VII. --- LESSONS LEARNED --- p.91
Chapter 7.1 --- Market Information and Industry Data --- p.91
Chapter 7.2 --- Decision Making --- p.92
Chapter 7.3 --- Management Practices --- p.92
Chapter 7.4 --- Simple and easy to implement strategies --- p.93
Chapter 7.5 --- Reliance on key Employees --- p.93
Chapter 7.6 --- Leadership Style --- p.94
Chapter 7.7 --- Importance of Cash Flows to Small Business --- p.95
Chapter 7.8 --- Delegation of Duties --- p.96
Chapter VIII. --- CONCLUSIONS --- p.98
APPENDIX
Chapter 1. --- EXAMPLE OF ADVERTISEMENT FROM MOULD MAKING SHOP --- p.100
Chapter 2. --- "MACHINERY, MOULD PRODUCTS AND WORKSHOP ENVIRONMENT OF CL" --- p.101
Chapter 3. --- PRODUCTION SCHEDULE FOR PLASTIC MOULDS --- p.106
Chapter 4. --- DISTRIBUTION OF CL'S SALES TO ITS CUSTOMERS … --- p.107
Chapter 5. --- RECORDED FINANCIAL STATEMENTS OF CL --- p.110
Chapter 6. --- ANTICIPATED FINANCIAL STATEMENTS OF CL --- p.118
BIBLIOGRAPHY --- p.124
Books on the topic "Plastic foams industry Case studies"
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Blaschka, Martina. Tupperware als Lebensform: Die Schüssel, die Party, die Beraterin : eine empirische Studie. Tübingen: Tübinger Vereinigung für Volkskunde, 1998.
Find full textConference papers on the topic "Plastic foams industry Case studies"
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Wenger, George M., Richard J. Coyle, Patrick P. Solan, John K. Dorey, Courtney V. Dodd, Anthony Primavera, and Robert Erich. "Case Studies of Brittle Interfacial Failures in Area Array Solder Interconnects." In ISTFA 2000. ASM International, 2000. http://dx.doi.org/10.31399/asm.cp.istfa2000p0355.
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Abstract A common pad finish on area array (BGA or CSP) packages and printed wiring board (PWB) substrates is Ni/Au, using either electrolytic or electroless deposition processes. Although both Ni/Au processes provide flat, solderable surface finishes, there are an increasing number of applications of the electroless nickel/immersion gold (ENi/IAu) surface finish in response to requirements for increased density and electrical performance. This increasing usage continues despite mounting evidence that Ni/Au causes or contributes to catastrophic, brittle, interfacial solder joint fractures. These brittle, interfacial fractures occur early in service or can be generated under a variety of laboratory testing conditions including thermal cycling (premature failures), isothermal aging (high temperature storage), and mechanical testing. There are major initiatives by electronics industry consortia as well as research by individual companies to eliminate these fracture phenomena. Despite these efforts, interfacial fractures associated with Ni/Au surface finishes continue to be reported and specific failure mechanisms and root cause of these failures remains under investigation. Failure analysis techniques and methodologies are crucial to advancing the understanding of these phenomena. In this study, the scope of the fracture problem is illustrated using three failure analysis case studies of brittle interfacial fractures in area array solder interconnects. Two distinct failure modes are associated with Ni/Au surface finishes. In both modes, the fracture surfaces appear to be relatively flat with little evidence of plastic deformation. Detailed metallography, scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and an understanding of the metallurgy of the soldering reaction are required to avoid misinterpreting the failure modes.
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Castelo, Adriano, David White, and Yinghui Tian. "Solving Downslope Pipeline Walking on Non-Linear Soil With Brittle Peak Strength and Strain Softening." In ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/omae2017-61168.
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In 2000 the first case of pipeline walking (PW) was properly documented when this phenomenon seriously impacted a North Sea high pressure and high temperature (HP/HT) pipeline (Tornes et al. 2000). By then, the main drivers of this problem were accordingly identified for the case studied. On the other hand, to study other aspects related not only to PW, the industry joined forces in the SAFEBUCK Joint Industry Project (JIP) with academic partners. As a result, other drivers, which lead a pipeline to walk, have been identified (Bruton et al. 2010). Nowadays, during the design stage of pipelines, estimates are calculated for pipeline walking. These estimates often use a Rigid-Plastic (RP) soil idealization and the Coulomb friction principle (Carr et al. 2006). Unfortunately, this model does not reflect the real pipe-soil interaction behavior, and in practice time consuming finite element computations are often performed using an Elastic-Perfectly-Plastic (EPP) soil model. In reality, some observed axial pipe-soil responses are extremely non-linear and present a brittle peak strength before a strain softening response (White et al. 2011). This inaccuracy of the soil representation normally overestimates the Walking Rate (WR) (a rigid plastic soil model leads to greater walking). A magnified WR invariably leads to false interpretations besides being unrealistic. Finally, a distorted WR might also demand mitigating measures that could be avoided if the soil had been adequately treated. Unnecessary mitigation has a very strong and negative effect on the project as whole. It will require more financial and time investments for the entire development of the project — from design to construction activities. Therefore, having more realistic and pertinent estimates becomes valuable not only because of budgetary issues but also because of time frame limits. The present paper will show the results of a set of Finite Element Analyses (FEA) performed for a case-study pipeline. The analyses — carried out on ABAQUS software — used a specific subroutine code prepared to appropriately mimic Non-Linear Brittle Peak with Strain Softening (NLBPSS) axial pipe-soil interaction behavior. The specific subroutine code was represented in the Finite Element Models (FEMs) by a series of User Elements (UELs) attached to the pipe elements. The NLBPSS case is a late and exclusive contribution from the present work to the family of available pipeline walking solutions for different forms of axial pipe-soil interaction model. The parametric case-study results are benchmarked against theoretical calculations of pipeline walking showing that the case study results deliver a reasonable accuracy level and are reliable. The results are then distilled into a simplified method in which the WR for NLBPSS soil can be estimated by adjusting a solution derived for RP and EPP soil. The key outcome is a genuine method to correct the WR resultant from a RP soil approach to allow for peak and softening behaviour. It provides a design tool that extends beyond the previously-available solutions and allows more rapid and efficient predictions of pipeline walking to be made. This contribution clarifies, for the downslope walking case, what is the most appropriate basis to incorporate or idealize the soil characteristics within the axial Pipe-Soil Interaction (PSI) response when performing PW assessments.
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Irmak, Firat, Sahil Karim, Nathan O’Nora, and Ali P. Gordon. "Establishing a Generic Stress-Life Framework for Single-Crystal Nickel-Base Superalloys." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-83276.
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Abstract Selection of materials to be used for components experiencing extreme conditions is a critical process in the design phase. Nickel-base superalloys have been frequently used for hot gas path components in the turbomachinery industry. These components are required to withstand both fatigue and creep at extreme temperatures during their service time. In general, the extreme temperature materials mostly embody polycrystalline, directionally solidified, and single crystal superalloys. Single crystallization has been utilized with nickel-base superalloys since 1980s. This method forms one grain by eliminating all of the grain boundaries, which has resulted with thermal, fatigue and creep properties superior to conventional alloys. It is essential for design engineers to predict accurate damage behavior and lifespan for these components to prevent catastrophic failures. This study presents generic elastic and stress-life models for single crystal nickel-base superalloys based on observed trends. Despite the development of over 50 variations of single crystal Nickel-base superalloys, the behavior of these alloys nominally follows similar mechanical behavior trends with respect to temperature and orientation. Temperature-, rate-, and orientation-dependence of these materials are studied. In this study, [001], [011] and [111] orientations are mainly considered. The goal is to eliminate extensive time and cost of experiments by creating parameters to be used in life calculations for generic single crystal alloys. While the stress-based approach to fatigue analysis of materials was the first to be developed, it continues to endure with broad usage in a wide variety of engineering applications. These models tend to be used for the cases with high number of cycles to failure behavior or called high-cycle fatigue (HCF) conditions. In this work, the total damage is divided into two different modules; fatigue and creep damages. Miner’s Rule is utilized to combine these modules. Models which can predict the cycles to failure data with the most usage-like conditions and require least amount of data are preferred. Parameters for the models are built on regression fits in comparison with a comprehensive material database. This database includes elastic, plastic, creep, and fatigue properties.
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Torgovnikov, Grigory, and Graham Brodie. "G. Brodieand, G. Torgovnikov. EXPERIMENTAL STUDY OF MICROWAVE SLOW WAVE COMB AND CERAMIC APPLICATORS FOR SOIL TREATMENT AT FREQUENCY 2.45 GHZ." In Ampere 2019. Valencia: Universitat Politècnica de València, 2019. http://dx.doi.org/10.4995/ampere2019.2019.9651.
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EXPERIMENTAL STUDY OF MICROWAVE SLOW WAVE COMB AND CERAMIC APPLICATORS FOR SOIL TREATMENT AT FREQUENCY 2.45 GHZ. G. Brodie and G. Torgovnikov University of Melbourne, 4 Water St, Creswick, Victoria 3363, Australia; e-mail: grigori@unimelb.edu.au Keywords: ceramic applicator, comb applicator, microwave, slow wave, soil microwave treatment In many cases in industry it is required to heat or treat surface layers of different material (soil, timber, concrete, plastics and so on) with microwaves (MW). Traditional MW irradiators (antennas) cannot provide heating only in the surface areas and energy penetrates deep into the material, where it decays exponentially due to normal attenuation. Therefore, energy losses, if a heating depth of 20 - 40 mm (for example to heat soil for killing weed seeds) is all that is required, are very significant. Therefore, it is required to develop special MW applicators for surface treatment to increase process efficiency. To address this problem, a slow wave (which is sometimes called a "surface wave" applicator) comb and ceramic structures, was studied. The main property of slow waves is that the energy concentration is very near impedance electrode – comb or ceramic plate surface. Previously, slow wave structures were used mostly as delay lines and as interaction circuits in MW vacuum devices, and their properties were explored only for these specific applications. The work objectives of this study were: design slow wave, ceramic and comb structure applicators for soil treatment at frequency 2.45 GHz;experimentally study the energy distribution from slow wave applicators in the soil;study of opportunities to use slow wave structures for surface soil layer heating; andrecommendations for practical use of new slow wave applicators. Comb and ceramic slab applicators for frequency 2.45 GHz operation were designed for the soil treatment on the bases of theoretical studies and computer modelling. The comb applicator was made from aluminium and the ceramic slab applicator was made from alumina (DC=9.8, loss tangent=0.0002). A 30 kW (2.45 GHz) microwave generator was used for experiments. Containers with soil were placed on the applicator surface. An auto tuner was used in MW system to provided good impedance matching of the generator and applicators (with soil on top). This resulted in practically no power reflection. The soil “Potting Mix Hortico”, with moisture content range 32-174% and density range 590-1070 kg/m3, was used for the experiments. Energy distribution in the soil was determined by temperature measuring in the soil using thermocouples, after MW heating. Distribution of temperature measuring points covered the whole volume of the soil along and across the applicator. Results of the experiments showed that the comb applicator provides maximum energy release in soil in the central vertical plane. The ceramic alumina applicator forms two temperature maximums in two vertical planes at a distance of about 40 mm from the central applicator plane and a minimum in the applicator central plane. The ceramic applicator provides better uniformity of energy distribution across the width of the applicator due to the two temperature maximums. It reduces overheating of the soil surface and energy losses. The depth of energy penetration provided by ceramic applicator is lower compared with the comb applicator. It means that the ceramic applicator provides better energy localization and more energy absorption in the soil surface layers compared with the comb applicator. To provide better uniformity of energy distribution across the ceramic applicator it is recommended to use ceramics with higher dielectric constants, such as in the range of 15-25, which will allow more energy to be released closer to the applicator surface. It will increase efficiency of MW energy use. The ceramic applicator is more effective for MW treatment of the soil surface areas and is recommended for practical use in machines for thermal treatment and sterilization of surface layers of the soil and other materials.
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Turnquist, Michael, and Ian Smith. "A Life-Cycle Approach to the Assessment of Pipeline Dents." In 2016 11th International Pipeline Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/ipc2016-64460.
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The application of in-line inspection (ILI) to assess pipelines for various anomalies is standard practice in the pipeline industry. When ILI data identifies the presence of anomalies such as denting or ovalization, current convention is to perform either a depth-based or strain-based assessment to assess the severity. Although a strain-based methodology is generally accepted in the pipeline industry, this approach does not address all of the primary damage mechanisms associated with pipeline dents. Assessment based upon either depth or strain alone may not only provide non-conservative results but also fail to properly rank dents in order of their true severity. A life-cycle assessment approach that considers the damage caused by the dent formation, the stress intensification effect of the dent profile, and the severity of future pressure cycling provides an improved understanding of the probability of failure, allowing for more informed integrity management decision making. Strain-based assessment of dents in pipelines is typically performed by calculating the local curvatures in the dent geometry as measured by ILI. Local strains are then calculated based on these local curvatures. However, this approach does not address that once a dent has been formed, continued pressure cycling at that location is what will ultimately cause a failure. The current strain-based methodology does not account for the severity of the pressure cycling at the dent. A new and innovative methodology has been developed which takes a life-cycle approach to the assessment of pipeline dents. This approach estimates the remaining life of a dent based on fatigue damage accumulation. Finite element analysis (FEA) is used to calculate various stress concentration factors (SCFs) based on the geometry of the dent. These SCFs are used to calculate an equivalent alternating stress for a unit pressure cycle event. Past representative pressure cycling data is gathered using a rainflow counting approach. The amount of damage accumulated during each pressure cycle is calculated using stress or strain based (S-N) fatigue curves; this allows for a damage rate to be calculated based on past operational history. A remaining life can be estimated based on this damage rate and an estimation of the initial fatigue damage accumulated during formation of the dent. This estimation is made based on previous elastic-plastic FEA of various scenarios which simulate the formation and shakedown of a pipeline dent. Case studies which explore the use of different assessment methods to analyze dents will be presented. A comparison of different assessment methodologies will illustrate the improved understanding of the probability of failure of dents based upon the life-cycle assessment.
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Prueter, Phillip E., and Brian Macejko. "Establishing Recommended Guidance for Local Post Weld Heat Treatment Configurations Based on Thermal-Mechanical Finite Element Analysis." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63581.
Full textAbstract:
Post weld heat treatment (PWHT) is an effective way to minimize weld residual stresses in pressure vessels and piping equipment. PWHT is required for carbon steels above a Code-defined thickness threshold and other low-alloy steels to mitigate the propensity for crack initiation and ultimately, brittle fracture. Additionally, PWHT is often employed to mitigate stress corrosion cracking due to environmental conditions. Performing local PWHT following component repairs or alterations is often more practical and cost effective than heat treating an entire vessel or a large portion of the pressure boundary. In particular, spot or bulls eye configurations are often employed in industry to perform PWHT following local weld repairs to regions of the pressure boundary. Both the ASME Boiler and Pressure Vessel (B&PV) Code and the National Board Inspection Code (NBIC) permit the use of local PWHT around nozzles or other pressure boundary repairs or alterations. Additionally, Welding Research Council (WRC) Bulletin 452 [1] offers detailed guidance relating to local PWHT and compares some of the Code-based methodologies for implementing local PWHT on pressure retaining equipment. Specifically, local PWHT methodologies provided in design Codes: ASME Section VIII Division 1 [2] and Division 2 [3], ASME Section III Subsection NB [4], British Standard 5500 [5], Australian Standard 1210 [6], and repair Codes: American Petroleum Institute (API) 510 [7] and NBIC [8] are discussed and compared in this study. While spot PWHT may be appropriate in certain cases, if the soak, heating, and gradient control bands are not properly sized and positioned, it can lead to permanent vessel distortion or detrimental residual stresses that can increase the likelihood of in-service crack initiation and possible catastrophic failure due to unstable flaw propagation. It is essential to properly engineer local or spot PWHT configurations to ensure that distortion, cracking of adjacent welds, and severe residual stresses are avoided. In some cases, this may require advanced thermal-mechanical finite element analysis (FEA) to simulate the local PWHT process and to predict the ensuing residual stress state of the repaired area. This paper investigates several case studies of local PWHT configurations where advanced, three-dimensional FEA is used to simulate the thermal-mechanical response of the repaired region on a pressure vessel and to optimize the most ideal PWHT arrangement. Local plasticity and distortion are quantified using advanced non-linear elastic-plastic analysis. Commentary on the ASME and NBIC Code-specified local PWHT requirements is rendered based on the detailed non-linear FEA results, and recommended good practice for typical local PWHT configurations is provided. Advanced computational simulation techniques such as the ones employed in this investigation offer a means for analysts to ensure that local PWHT configurations implemented following equipment repairs will not lead to costly additional damage, such as distortion or cracking that can ultimately prolong equipment downtime.