L'objectif de ce travail de recherche est le développement d'un outil numérique capable de simuler le comportement d'infrastructures sensibles soumises à des charges dynamiques extrêmes sous l'effet d'aléas naturels ou humains tels que les impacts aériens. L'étude propose pour ce faire une modélisation 3D par éléments discrets, capable de décrire des états de destructions avancés en obtenant des macro-fissures et des fragments réalistes grâce à la nature discontinue du modèle.Dans un premier temps, on a étudié de manière exhaustive l'influence des paramètres de création du maillage sur les caractéristiques dudit maillage et sur le comportement macroscopique du béton. Ensuite, on a transformé le modèle de charge dynamique en une modélisation plus réaliste de l'énergie de rupture dynamique en contrôlant l'augmentation de distance limite maximum à l'interaction. Par ailleurs, on a défini une condition de ratio entre la taille des éléments discrets et celle des éléments finis pour s'assurer d'un contact correct entre eux.La procédure d'identification des paramètres du modèle est réalisée en simulation numérique avec des essais en laboratoire: Compression et traction quasi-statiques, essai tri-axial à haut confinement, écaillage dynamique. Enfin, la fiabilité de l'approche est vérifiée sur trois essais différents d'impact violent:1) Perforation et pénétration de projectiles à tête ogivale dans des cibles cylindriques confinées (CEA-Gramat)2) Essais d'impact tranchant de projectile avec une géométrie homothétique particulière sur des dalles en béton (Erzar) / The objective of this work is development of a numerical tool capable to simulate sensitive infrastructures subjected to severe dynamic loadings due to natural or manmade hazards, such as aircrafts impacts. This study proposes a 3D discrete element method able to predict advance damage states obtaining realistic macro-cracks and materials fragments due to its discontinue nature.We thoroughly studied the influence of mesh creation parameters on the mesh characteristics and on the macroscopic concrete behaviour. Then, we modified the constitutive model for dynamic loading with a more realistic modelling of the dynamic fracture energy by controlling the increase of the maximum distance limit at the interaction scale. In addition, we defined a condition for ratio between the size of finite and discrete elements for proper contact between them.The identification procedure for the parameters of the constitutive model is analysed with simulation on laboratory test: quasi-static compression and tension, high confinement triaxial and dynamic spalling. Finally, the reliability of our approach is verified on three different types of hard impact test: 1) perforation and penetration of ogive-nosed projectiles on confined cylindrical targets (CEA-Gramat); 2) edge-on impact tests of projectiles with a particular homothetic geometry on concrete tiles (Erzar); 3) drop-weight impact on a reinforced concrete beam (University of Toronto).

The objective of this research was to better understand how impact angle influences headform dynamic response and brain tissue deformation. A bare headform was impacted using a pneumatic linear impactor at 5.5 m/s. The impacts were directed on the front and side location at angles of 0, 5, 10 and 15° rightward rotations as well as -5, -10 and -15° (leftward) rotations at the side to examine the characteristics of the head and neckform on the results. Peak resultant linear and rotational accelerations from the headform as well as peak maximum principal strain (MPS) and von Mises stress (VMS) estimated from a brain finite element model were used to measure the effect of impact angle. Significant results were dependent upon the impact angle and location as well as the dependent variable used for comparison (p <0.05). Impact angle produced significant differences in rotational acceleration and MPS at both the front and side; however angle only had an effect on VMS and linear acceleration at the front and side locations, respectively. These findings show that the effect of impact angle is asymmetrical and is specific to the dependent variable. This study suggests that varying impact angle alone may not be as influential on headform dynamic response and brain tissue deformation and that the severity of an impact may be more of a function of how both location and angle create high risk conditions.

Social Impact Assessment (SIA) is the process of assessing the social consequences that are likely to follow specific policy actions or project development. SIA has not been widely adopted and is said to be the orphan of the assessment process. Using Environmental Assessment (EA) however, there are two primary limitations to EA: first, EA is inherently biased toward the biophysical environment, and social impacts, when considered, are only considered in an indirect or secondary manner; second, EA is targeted at the project level, where many alternatives that may have met the larger goals have been rejected. These limitations are reflected in Canadas agricultural sector where SIAs are rarely, if ever, undertaken. Agriculture is responsible for approximately ten percent of total greenhouse gas (GHG) emissions in Canada, and several better management practices (BMP) have been suggested for managing these emissions in Canadian agriculture. However, there has not been a strategic assessment of the on-farm socioeconomic effects of such programs, nor the geographic implications of a one-size-fits-all policy solution. <p>This paper presents a higher level strategic assessment of alternative policy options for managing greenhouse gas emissions in Canadian agriculture. Data are collected using a stakeholder survey assessment, and the process is guided by a seven-phase strategic environmental assessment framework. Using this strategic framework, the on-farm social impacts of alternative greenhouse gas mitigation programs are assessed. Data are aggregated using multi-criteria weighting techniques. Stakeholder preference structures for the alternatives set are identified as well, the results of the SIA identified adoption of zero till practices as the most socially acceptable alternative. The research results suggest that a one-size-fits-all GHG mitigation policy would not be acceptable from a social perspective. The implications of include such issues as: the applicability of regional policies based on soil zone, alternatives to governmental top down hierarchical policies, and the necessity for collaboration and meaningful dialogue between on-farm individuals and policy makers. Adoption of a GHG mitigation policy in Canada will require education and collaboration between all affected stakeholders and decision makers. The application of a strategic framework illustrates how the SIA process is enhanced when an assessment is completed at the plan, policy, and program level it enables proactive consideration of the social effects on par with the biophysical effects, and it facilitates consideration of a broad range of alternatives, in support of sustainable development principles.

Social Impact Assessment (SIA) is the process of assessing the social consequences that are likely to follow specific policy actions or project development. SIA has not been widely adopted and is said to be the orphan of the assessment process. Using Environmental Assessment (EA) however, there are two primary limitations to EA: first, EA is inherently biased toward the biophysical environment, and social impacts, when considered, are only considered in an indirect or secondary manner; second, EA is targeted at the project level, where many alternatives that may have met the larger goals have been rejected. These limitations are reflected in Canadas agricultural sector where SIAs are rarely, if ever, undertaken. Agriculture is responsible for approximately ten percent of total greenhouse gas (GHG) emissions in Canada, and several better management practices (BMP) have been suggested for managing these emissions in Canadian agriculture. However, there has not been a strategic assessment of the on-farm socioeconomic effects of such programs, nor the geographic implications of a one-size-fits-all policy solution. <p>This paper presents a higher level strategic assessment of alternative policy options for managing greenhouse gas emissions in Canadian agriculture. Data are collected using a stakeholder survey assessment, and the process is guided by a seven-phase strategic environmental assessment framework. Using this strategic framework, the on-farm social impacts of alternative greenhouse gas mitigation programs are assessed. Data are aggregated using multi-criteria weighting techniques. Stakeholder preference structures for the alternatives set are identified as well, the results of the SIA identified adoption of zero till practices as the most socially acceptable alternative. The research results suggest that a one-size-fits-all GHG mitigation policy would not be acceptable from a social perspective. The implications of include such issues as: the applicability of regional policies based on soil zone, alternatives to governmental top down hierarchical policies, and the necessity for collaboration and meaningful dialogue between on-farm individuals and policy makers. Adoption of a GHG mitigation policy in Canada will require education and collaboration between all affected stakeholders and decision makers. The application of a strategic framework illustrates how the SIA process is enhanced when an assessment is completed at the plan, policy, and program level it enables proactive consideration of the social effects on par with the biophysical effects, and it facilitates consideration of a broad range of alternatives, in support of sustainable development principles.

Activities, conducted in the logistics sector, contribute to pollute the world. Especially, road transportation contaminates the environment with the release of exhaust emissions. Transport volumes as well as the proportion of the road sector are constantly rising, which intensifies its environmental impacts. In order to determine the main culprits of pollution, Environmental Impact Analysis (EIA) are used. These concepts are mostly ambiguous, fuzzy and hard to present in a comprehensive way. The main purpose of the present thesis is to develop an analysis in order to investigate the environmental impacts of road transportation along a certain supply chain. An academic resource was used as database, in order to develop and test an exhauste mission calculation in cooperation with a case company. Besides CO2, this assessment also focuses on the measurement of other exhauste missions like Nox, PM or CO. Furthermore, economic factors like, costs caused per transport are calculated. Aspects, like capacity utilization, the use of environmentally friendly tires or eco-friendly driving styles, are included in the analysis. These factors influence fuel consumption and thus the final production of exhaust emissions. A detailed description of each factor and calculation step is illustrated in this thesis. Due to a high complexity of transportation, this analysis is limited to road transportation. The fundament of the analysis builds the categorization of crafts due to the Euro standards. Hence, just transports conducted with crafts, manufactured within the European Union, can be evaluated. A validation test and in-depth interviews were conducted in order to approve the practicability of the developed assessment. During this process, strengths and weaknesses of the analysis were identified. Finally, the analysis is critically examined by showing its application constraints as well as prospective development opportunities. An enlargement, to include other transport modes, material handling activities in order to measure impacts during intermodal transportation along a whole transportation chain, is a prospect outlook.

Although recent brownfields redevelopment research using theories of real estate valuation and neighborhood change have indicated negative effects on surrounding residential housing, little evidence exists to show price impacts and sociodemographic change after remediation. This study examines the extent and size of the economic impact of Superfund sites on surrounding single-family residential properties before and after remediation in Miami-Dade County and examines trends for contemporaneous sociodemographic changes. The study combines the economic impact from changes in environmental quality with contemporaneous sociodemographic changes within the purview of environmental and social justice. This study uses spatial hedonic price modeling on a comprehensive dataset of property-level data, with corresponding sales prices of housing transactions while controlling for other structural, neighborhood, and submarkets characteristics for assessing economic impact. Findings revealed that housing sales prices for single-family residential properties significantly increases as distance to the nearest contaminated Superfund increases. Following remediation, this negative impact declined and housing values increased significantly in neighborhoods with remedied Superfund sites albeit more so in low housing submarkets than premium submarkets. Spatial hedonic models outperformed traditional OLS models in presenting unbiased efficient parameter estimates, correcting for spatial dependence. Although no evidence for gentrification was observed, there existed significant differences between certain sociodemographic characteristics of neighborhoods around contaminated Superfund sites and those of properties located elsewhere leading to concerns of environmental and social justice. Findings suggest that low-income minority populations are more likely to be living in neighborhoods around contaminated Superfund sites and experience a greater negative effect on housing sales prices; these sites are also less likely to be remedied as compared to sites located elsewhere. The findings highlight not only the revealed preferences of homeowners with respect to environmental disamenities, but also help inform policymakers and researchers of the impact of brownfields redevelopment on economic and sociodemographic characteristics of a growing urban region with evolving cultural and social diversity. Incorporating influences of housing submarkets, neighborhood amenities, and spatial dependence help provide a holistic and comprehensive model for examining environmental disamenities and provide a better understanding for neighborhood change.

The high strength, light weight, and flexibility of fabric protection systems makes them the preferred solution for a number of ballistic applications. Examples include body armor, fan blade containment for jet engines, and orbital debris shielding. In general, these protection systems employ plain woven fabric, most suitable for flat or gently curved geometries. Highly curved surfaces, such as personnel extremities, may be more effectively protected using fabrics of different weaves. This dissertation presents the first numerical model developed to simulate ballistic impacts into plain, harness satin, twill, and basket weave fabrics. It extends previous work on hybrid particle-finite element methods developed for fabric modeling. The extended formulation closely replicates the tensile load response and contact-impact dynamics of highly flexible yarns, by generalizing the kinematic model and density interpolation used in previous work. The formulation has been validated in three dimensional simulations of impact experiments conducted to investigate the effects of weave type on fabric ballistic performance. / text

This investigation focuses on two well-preserved impact structures developed in sedimentary target rocks: the ~23.5 Ma old Haughton structure, Canada, and the ~14.5 Ma old Ries structure, Germany. The aim of this study was to investigate the effects of hypervelocity impact into sedimentary targets. The study reveals that a series of different impactites are present at Haughton, the bulk of which comprise a groundmass of impact-generated melts (calcite + silicate glass ± anhydrite). Thus, carbonates, evaporites, sandstones, and shales underwent shock melting during the Haughton impact event. The shock melting of impure carbonates resulted in the generation of Mg–Ca–Si-rich melts that crystallized calcite during rapid cooling. The residual melt quenched to Mg–Si-rich glass. These impactites should, therefore, be classified as clast-rich impact melt rocks or impact melt breccias, and not clastic matrix breccias as previously held. Ries surficial suevites are reinterpreted as clast-rich impact melt rocks or impact melt breccias. Four main types of impact melt glass are present, in contrast to previous studies that recognized only one type. These results are at odds with the current, generally accepted, definition of suevite. Given that the Ries is the original type occurrence of ‘suevite’, some redefinition of the term suevite may be in order. Furthermore, it is clear that sedimentary rocks, as well as crystalline rocks, were shock melted during the Ries impact event. The results of this study are, therefore, incompatible with previous models in which the zone of melting is restricted to the crystalline basement. It is apparent that impact melting in sedimentary targets is much more common than previously thought. Furthermore, there is no unequivocal evidence for the decomposition of carbonates or evaporites at any terrestrial impact site. Many previous assumptions about the response of sedimentary rocks during hypervelocity impact events are, therefore, incorrect. The products of impact into sedimentary targets may appear very different from those developed in crystalline targets. However, microscopic imaging and analysis suggests that these seemingly different lithologies may be genetically equivalent. Thus, the apparent ‘anomaly’ between the amount of impact melt rocks formed in sedimentary and crystalline targets may be due to a misinterpretation of the rock record.

As a consequence of the gradually expanding aviation network, civil aircrafts are occupying an increasingly high proportion of the transport industry. Air transport now dominates the intercity rapid transit, long-distance passenger transport, international passenger and freight transport, and specific regional transport, advantaged as it is by fast, convenient, comfortable and safe options. Nevertheless, the potential adverse impact on the environment of air transport, specifically, in the case of this research, the pollutants generated during aircraft production remain a concern. Using the A319 as the main research object, this thesis will conduct a life cycle assessment research about its environmental impact. Moreover, it will focus on the impact brought by the application of composite materials to the entire life cycle environmental influence of the aircraft, particularly the material production and disposal process. At the same time, a contrast with the B737-800 aircraft will be made due to their different composite material use rate. Firstly, the inventory list is formed by collecting data about the weight and material of every component in the aircraft, the input and output information of the composite material manufacturing process, the disposal situation of the aircraft and the treatment of composite material. Secondly, the impact assessment of the aircraft is conducted to examine their environmental influence. During the assessment, each life stage and the whole life cycle of the aircrafts is assessed, and a comparison between these two aircraft types is made. Finally, according to the impact assessment result, the environment load increase brought by the manufacturing of composite material and the decrease of the environment impact due to the weight reduction character of composite material is calculated and compared. From this research, the conclusion that the use of composite material has a positive effect on decreasing the environmental impact of the whole life cycle of the aircraft is obtained. This will enable aircraft manufacturers to target these reas for improvement, to produce more comfortable, environment friendly and market competitive aircraft.

Environmental Impact Assessment (EIA) is a process that seeks to reduce the negative environmental consequences of listed development activities, which could have a detrimental effect on the environment, in the advance of their implementation, and a requirement of legislation in South Africa. An important element of the systematic EIA process is the submission of an environmental impact or scoping report or an environmental impact report (EIR) to the relevant governmental department, interested and affected parties and/or specialist for review to determine the report's adequacy before a project can be authorised or if further information is required. The information made available in reports to decision-makers with regard to developments with the potential of affecting explosive projects, plays a significant role in the authorisation of the project after the authority review process, which is dependent on the quality of the report. In order to contribute more effectively to sustainable development, more attention must be placed on assessing the quality of ElA's as part of determining how effectively EIA has been functioning in South Africa; hence this study is aimed at assessing the quality of EIA assessment reports of four projects with the potential of impacting on explosive industry projects. The objectives of the study included the review by independent reviewers of the quality of four-selected impact reports using a checklist, analysis of the review process results and provision of recommendations to improve the quality of environmental impact reports for-explosive projects. Based on the review results it is concluded that the quality of the four reports for-explosive projects. Based on the review results it is concluded that the quality of the four reports were of an acceptable standard, although certain areas were found poorly performed i.e. improvement with regard to identification of key impacts and considerations of alternatives and mitigation as well as the control and treatment of waste. Otherwise the review method is fairly robust and consistent and therefore can be seen as a reliable indication of EIR quality. The following was recommended to improve the quality of the reports for explosive projects: The use of a quality review checklist for explosive projects by EIA practitioners and authorities to be used as an additional tool to the EIA regulations (DEAT 2002) and the Integrated Environmental Management series (DEAT 2002) can further improve the quality of the El reports for explosive projects. • The use by EIA practitioners of an explosive review checklist will assist in ensuring that all key aspects are addressed before submission to relevant authorities, i.e. the report contains all pertinent information and is technically sound, the report is set-up clearly and coherently organized and presented so that it can be understood and that it has addressed all the key issues to make a decision about the proposed development. This will further assist in fast-tracking the approval process often delayed by the request of additional information from the applicant as a result of inadequate reports. • Regular use of the review checklist by EIA practitioners and authorities for ascertaining the quality of the environmental impact reports will contribute to a baseline of EIR quality for evaluating EIA practice for explosive projects under the new regulations promulgated in June 2006. / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2009.