PVP2008-61243 UNIQUE METHOD FOR GENERATING DESIGN EARTHQUAKE TIME HISTORIES

ABSTRACT A method has been developed which takes a seed earthquake time history and modifies it to produce given design response spectra. It is a multi-step process with an initial scaling step and then multiple refinement steps. It is unique in the fact that both the acceleration and displacement response spectra are considered when performing the fit (which primarily improves the low frequency acceleration response spectrum accuracy). Additionally, no matrix inversion is needed. The features include encouraging the code acceleration, velocity, and displacement ratios and attempting to fit the pseudo velocity response spectrum. Also, "smoothing" is done to transition the modified time history to the seed time history at its start and end. This is done in the time history regions below a cumulative energy of 5% and above a cumulative energy of 95%. Finally, the modified acceleration, velocity, and displacement time histories are adjusted to start and end with an amplitude of zero (using Fourier transform techniques for integration). INTRODUCTION Time history analysis is an important technique for structural seismic analysis especially when the evaluated structural response is nonlinear. To perform such an analysis, a representative earthquake time history (or seed time history) is established for a structure being evaluated. To ensure that the variability in the response is addressed, a design response spectrum is then established using code guidance (e.g. ASCE 4-98 [1]). Because the design response spectrum does not match the response of the seed time history, the seed time history cannot be used for design evaluation. Instead, a modified time history must be used that is based on the seed time history, but provides a response defined by the design response spectrum. The method described in this paper is a way to modify the seed time history in such a way that it produces the design response

PVP2008-61244 UNIQUE METHOD FOR GENERATING DESIGN EARTHQUAKE TIME HISTORY SEEDS

ABSTRACT A method has been developed which takes a single seed earthquake time history and produces multiple similar seed earthquake time histories. These new time histories possess important frequency and cumulative energy attributes of the original while having a correlation less than 30% (per the ASCE/SEI 43-05 Section 2.4 [1]). They are produced by taking the fast Fourier transform of the original seed. The averaged amplitudes are then pared with random phase angles and the inverse fast Fourier transform is taken to produce a new time history. The average amplitude through time is then adjusted to encourage a similar cumulative energy curve. Next, the displacement is modified to approximate the original curve using Fourier techniques. Finally, the correlation is checked to ensure it is less than 30%. This process does not guarantee that the correlation will be less than 30% for all of a given set of new curves. It does provide a simple tool where a few additional iterations of the process should produce a set of seed earthquake time histories meeting the correlation criteria. INTRODUCTION Time history analysis is an important technique for structural seismic analysis especially when the evaluated structural response is nonlinear. To perform such an analysis, a representative earthquake acceleration time history (or seed acceleration time history) is established for a structure being evaluated. Manipulations of the seed are then performed to create a modified acceleration time history (or design acceleration time history) that produces a design acceleration response (per the ASCE/SEI 43-05 Section 2.4 [1]). This design acceleration time history can then be used for seismic analysis. Depending on the type of seismic analysis being performed, several design acceleration time histories may be required. The method described in this paper is a way t

Sawing Optimisation for Block Panel's Production of Portuguese West Littoral Maritime Pine Radial Boards 1

Abstract. Increasing wood demand as raw material and the necessity to adjust each end use to the characteristics and properties of each wood has been improving the employ of round wood of small dimensions as well as low quality sawn wood. In this case we may include radial boards and the two adjacent tangential boards, even if obtained from large round wood. The available technological processes, mostly based on the identification and location of one of the most important wood defects -the knots -tend to maximize the utilisation level of small wood so as to improve quality and productivity. Maritime pine radial boards are the worst sawn pieces concerning presence of knots on more or less distant whorls along the stem. However, although being an unfavourable characteristic of the species, knot concentration on bands, separated by long annual height growth, allows the utilization of board wood in between. This paper aims to estimate mean values of number, size, location, condition and shape of knots on a sample of 161 radial boards from 38 maritime pine trees, collected in three pine forests located along the Portuguese littoral west coast. Based upon data collected in the stand and in the sawmill, it's also simulated the optimization of clean wood for sawing, in order to produce block board panels. To simulate lath profit, was taken account of tree provenance, statute in the stand, dbh, board mean diameter, number of knot bands and log ranking in the tree. The lath dimensions usually utilized by block boards panels industry were considered. Key words: Pinus pinaster; knots; laths profit; block board panels; modelling Sumário. A crescente procura de madeira como matéria prima e a necessidade de adequar as características e propriedades de cada tipo de madeira ao uso final pretendido, tem promovido o emprego de madeira redonda de pequenos diâmetros e de madeira serrada de menor qualidade. As tábuas radiais e as duas tangenciais adjacentes, mesmo se extraídas dos toros de maiores dimensões, podem estar, naturalmente, incluídas neste caso. Os processos tecnológicos disponíveis, a maioria baseados na identificação e localização de um dos mais importantes defeitos da madeira -os nós, tendem a maximizar a taxa de aproveitamento de peças mais pequenas de modo a que se atinjam melhores qualidade e produtividade. As tábuas radiais de pinheiro bravo são as peças serradas de pior qualidade no que respeita à presença de nós ao longo das tábuas. Contudo, sendo uma característica tecnológica desfavorável da espécie, a concentração de nós em bandas, separadas por longos crescimentos em altura, permite uma mais fácil utilização da madeira nos entrenós. Este trabalho pretende estimar o valor médio do número, tamanho, localização, estado e forma dos nós de uma amostra de 161 tábuas radiais extraídas de 38 pinheiros provenientes de três matas localizadas no litoral oeste de Portugal. Simula-se, ainda, a optimização da serragem de madeira isenta de nós para o fabrico de painéis de lamelados colados a partir da informação disponível na mata e na serração. A simulação do aproveitamento em ripas é efectuada através da proveniência, estatuto da árvore no povoamento, dap das árvores, diâmetro médio das tábuas, número de nós por banda e posição do toro na árvore. Consideram-se as dimensões de ripa mais utilizadas por esta indústria. Palavras-chave: Pinus pinaster; nós; aproveitamento em ripas; lamelado colado; modelação Résumé. La demande croissante en bois comme matière première, et la nécessité d'ajuster les caractéristiques et propriétés de chaque type de bois à l'usage final prétendu, pousse l'emploi de bois rond avec des plus petits diamètres et de bois sciés de qualité inférieure. Les planches radiales et les deux tangentielles adjacentes, toutes extraites des billons de plus grandes dimensions sont, naturellement, inclues dans ce cas. Les procédures technologiques disponibles, la plupart basées sur l'identification et la localisation d'un des plus importants défauts du bois -les noeuds, tendent à maximiser la taxe de profit des pièces plus petites de façon à atteindre une meilleure qualité et productivité. Les planches radiales de pin maritime sont les pires pièces en ce qui concerne la pré-sence de noeuds en verticilles sur les tiges. Toutefois, ceci étant une caractéristique technologique défavorable de l'essence, la concentration des noeuds en bandes, séparées par des longues pousses en hauteur, permet une utilisation du bois plus facile au niveau des entre--noeuds. Ce travail prétend estimer la valeur moyenne du nombre, grandeur, localisation, état et forme des noeuds d'un échantillon de 161 planches radiales extraites de 38 pins de trois forêts le long du littoral ouest du Portugal. On simule aussi l'optimisation du sciage du bois sans noeuds pour la fabrication de lamellés collés, d'après l'information disponible en forêt et en scierie. La simulation du profit en planches est effectuée en fonction de la provenance, du statut et du dhp des arbres et du diamètre moyen des planches, nombre de noeuds par bande et position du billon sur l'arbre. Les dimensions de planche les plus utilisées pour cette industrie sont considérées

IPC02-27103 NATURAL HAZARD DATABASE APPLICATION -A TOOL FOR PIPELINE DECISION MAKERS

ABSTRACT Trans Mountain Pipe Line Company Ltd. (TMPL) owns and operates an 1146 km NPS 24 low vapor pressure petroleum products pipeline between Edmonton, Alberta and Burnaby, British Columbia. In 1998 TMPL retained BGC Engineering Inc. (BGC) to start a three-phase geotechnical and hydrotechnical hazard assessment of the right of way (ROW) from Hinton, Alberta to Kamloops, British Columbia. As part of this work GroundControl was asked to develop an electronic database with which to capture the information generated by BGC during the hazard assessment work. This paper describes the development and evolution of the database application that accompanied the study to quantitatively assess and prioritize the geotechnical and hydrotechnical hazard potential along the pipeline. This paper describes how the database provides TMPL employees across British Columbia and Alberta access to the current results of the hazard assessment plus supporting information such as multi-temporal images and internal and 3rd party reports about the pipeline. The purpose of the database and the unique architecture and functionality that accommodates ongoing monitoring and inspections of slopes and stream crossings is provided. Database security, access, and information sharing unique to TMPL are also described. Benefits and costs of the application plus technical and business challenges overcome by TMPL, BGC, and GroundControl are discussed. Recommendations from TMPL and GroundControl for similar information management initiatives are provided and future work is described. This paper is targeted to pipeline managers who are looking for economical, practical, and innovative information management solutions for managing their natural hazards. (Keywords: database, hazard, risk, pipeline, geotechnical, hydrotechnical, landslide, GIS, river, stream). NOMENCLATURE Database -A collection of data and objects related to a particular topic or purpose. A database can contain tables, queries, forms, and reports. Database Application -Custom programmed functionality built around a collection of database objects designed for a specific purpose. The hazard management tool described in this paper is a database application. Field -An element of a table that contains a specific item of information, such as last name. A column or cell in a table represents a field. Many fields often comprise a single row. On a form, a control, such as a text box, is used to display data from a field. Record -A collection of data about a hazard, an inspection, or some other item. A record is represented as a row in table, or query. Control -A graphical object, such as a text box, a check box, a command button, or a rectangle, that are placed on a form or report to display data, perform an action, or make the form or report easier to read. Form -A database object on which controls are placed for taking actions or for entering, displaying, and editing data in fields. Data in tables are often displayed with a form. Report -A database object that presents information formatted and organized according to user specifications. Examples of reports are summaries for a single hazard, a list of hazards, and reports that include photos and text. The results of query are often displayed in reports. Proceedings of IPC'02 Hazard -A description of the landslide or hydrotechnical event, including magnitude plus a quantitative or qualitative description of probability of occurrence. In this paper hazard is expressed as a numeric hazard score. Risk -The expected loss resulting from a hazard being triggered and impacting one or more elements. Risk is formally expressed in monetary terms. BACKGROUND In the last decade, Natural Hazard and Risk Management (NHRM) has become a widespread tool for multinational corporations. Proper risk management requires that the natural hazard be identified, assessed, and then managed in order to reduce its impact on public safety and the environment. However the management of natural hazards is not the sole responsibility of the engineering or environmental departments. The adoption of formalized risk management encourages an interdisciplinary approach to facility management that requires inputs from engineering, environmental, operational, legal, and financial departments. Database applications are often at the hub of this integrated approach as they provide shared access to data and tools necessary for the quantification of hazards and risk. Database applications are also there to help manage the diverse and detailed information that is collected over numerous cycles of hazard identification, monitoring, and mitigation. For the above reasons, TMPL required that a database application be constructed to conform to the four phase NHRM methodology developed by BGC. This paper describes that application

TECHNICAL BASIS AND APPLICATION OF NEW RULES ON FRACTURE CONTROL OF HIGH PRESSURE HYDROGEN VESSEL IN ASME SECTION VIII, DIVISION 3 CODE

ABSTRACT As a part of an ongoing activity to develop ASME Code rules for the hydrogen infrastructure, the ASME Boiler and Pressure Vessel Code Committee approved new fracture control rules for Section VIII, Division 3 vessels in 2006. These rules have been incorporated into new Article KD-10 in Division 3. The new rules require determining fatigue crack growth rate and fracture resistance properties of materials in high pressure hydrogen gas. Test methods have been specified to measure these fracture properties, which are required to be used in establishing the vessel fatigue life. An example has been given to demonstrate the application of these new rules

Theoretical basis for extrapolation of calibration data of PTC 6 throat tap nozzles,

Introduction This paper was developed because page and space limitations prevented us from including derivations in our original paper We have also tried to include all pertinent information on flat plate boundary layer theory, which is the basis for our method of predicting the coefficient of discharge at higher Reynolds number using calibration data at lower Reynolds numbers. Theoretical numerical values needed for calculations were taken from Schlichtin

HEAT TRANSFER ANALYSIS OF RECUPERATIVE AIR PREHEATER

Abstract: Steam generators are very complex class of pressure vessels. It contains many accessories for the generation of required steam quality. The prime motto of industrial steam generator is to generate steam at medium pressure (MP), low pressure (LP) steam at required pressure temperature and quantity for the process industry like sugar, paper, jute and chemical industries. LP and MP steam after expansion in the turbine from super saturation is utilized by process industry. In the present work Air Preheater, one of the accessories of the steam generator is analysed. Air preheaters make a considerable contribution to the improved overall efficiency of fossil-fuel-fired power plants. In this study, a theoretical design of Recuperative Primary Air preheater with In-line tube arrangement and a combination of fluid dynamics analysis with theoretical value. The model enables heat transfer of the flue-gas flow through the air preheater as well as the tubular heat transfer and the resulting temperature distribution in the matrix of the preheater. The present work is carried in Mysore Paper Mills (MPM) Bhadravathi, CFD (Computational Fluid Dynamics) analysis of recuperative air preheater is carried out using ANSYS CFX-12.1.The analysis of flue gas flow phenomenon and air flow phenomenon are discussed using Laminar model, k-ε model, k-ω model and SST model. The parameters like temperature distribution, heat flux, pressure drop, velocity, are also discussed. An increase of 2.7% in boiler efficiency was found out with incorporation of this design, their by an increase in the air inlet temperature of about 60℃ is been observed