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• 21. [Article] No More Freeways: Urban Land Use-Transportation Dynamics without Freeway Capacity Expansion

  Observations of the various limitations of freeway capacity expansion have led to a provocative planning and policy question – What if we completely stop building additional freeway capacity. From a theoretical ...

  Citation × Citation Citation Abstract Copy Title: No More Freeways: Urban Land Use-Transportation Dynamics without Freeway Capacity Expansion Author: Zhang, Lei, Xu, We Year: 2011 Observations of the various limitations of freeway capacity expansion have led to a provocative planning and policy question – What if we completely stop building additional freeway capacity. From a theoretical perspective, as a freeway transportation network matures, there exists a saturation point beyond which any additional freeway capacity would only be counterproductive from a welfare point of view, and worsen the existing urban transportation problems. Traditional benefit/cost analysis of individual freeway capacity expansion projects often ignores long-term induced demand and land use changes and does not represent a systems approach to this important theoretical issue. From a practical perspective, a no-more-freeway policy can relieve transportation funds for other potentially more effective usages, such as improving urban arterial street system, improving transit level of service and coverage, implementing demand management and pricing strategies, and facilitating more efficient land use patterns (e.g. high density in-fill and transit-oriented developments). This research answers the following critical land use-transportation planning questions. Improved knowledge on these issues should benefit planers and decision-makers who pursue mobility and sustainability objectives and have the power to shape future cities. (1). Under what conditions will freeway capacity expansion become counterproductive to urban planning objectives (where is the saturation point)? (2). How will land use and transportation evolve under a “No-More-Freeway” policy? (3). What are the implications of such a policy on congestion, land use efficiency, transportation finance, and social welfare? (4). What is the impact of a less restrictive “No-More-Freeway” policy that only allows private-section freeway investments and relieves public-section freeway investments for other compelling transportation needs. The analysis in this project builds upon a modeling tool, ABSOLUTE, developed by the P.I. in previous research projects. ABSOLUTE is an Agent-Based Simulator Of Land Use-Transportation Evolution, which translates planning policies such as the “No-More- Freeway” policy into alternative urban growth paths and possibly urban growth equilibria (land use and transportation system equilibria). Due to the “Small Start” nature of this OTREC project, the analysis focuses primarily on stylized urban areas, and empirical analysis of the “No-More- Freeway” policy is only conducted for one policy scenario on the Twin Cities, MN, area. Title: No More Freeways: Urban Land Use-Transportation Dynamics without Freeway Capacity Expansion Author: Zhang, Lei, Xu, We Year: 2011 Observations of the various limitations of freeway capacity expansion have led to a provocative planning and policy question – What if we completely stop building additional freeway capacity. From a theoretical perspective, as a freeway transportation network matures, there exists a saturation point beyond which any additional freeway capacity would only be counterproductive from a welfare point of view, and worsen the existing urban transportation problems. Traditional benefit/cost analysis of individual freeway capacity expansion projects often ignores long-term induced demand and land use changes and does not represent a systems approach to this important theoretical issue. From a practical perspective, a no-more-freeway policy can relieve transportation funds for other potentially more effective usages, such as improving urban arterial street system, improving transit level of service and coverage, implementing demand management and pricing strategies, and facilitating more efficient land use patterns (e.g. high density in-fill and transit-oriented developments). This research answers the following critical land use-transportation planning questions. Improved knowledge on these issues should benefit planers and decision-makers who pursue mobility and sustainability objectives and have the power to shape future cities. (1). Under what conditions will freeway capacity expansion become counterproductive to urban planning objectives (where is the saturation point)? (2). How will land use and transportation evolve under a “No-More-Freeway” policy? (3). What are the implications of such a policy on congestion, land use efficiency, transportation finance, and social welfare? (4). What is the impact of a less restrictive “No-More-Freeway” policy that only allows private-section freeway investments and relieves public-section freeway investments for other compelling transportation needs. The analysis in this project builds upon a modeling tool, ABSOLUTE, developed by the P.I. in previous research projects. ABSOLUTE is an Agent-Based Simulator Of Land Use-Transportation Evolution, which translates planning policies such as the “No-More- Freeway” policy into alternative urban growth paths and possibly urban growth equilibria (land use and transportation system equilibria). Due to the “Small Start” nature of this OTREC project, the analysis focuses primarily on stylized urban areas, and empirical analysis of the “No-More- Freeway” policy is only conducted for one policy scenario on the Twin Cities, MN, area. Close

• 22. [Article] Land Use and Growth Impacts from Highway Capacity Increases

  This analysis examined the historical relationship between land use changes and the location of capacity increasing highway projects in the State of Oregon from 1970 to 1990. Aerial photography for 18 ...

  Citation × Citation Citation Abstract Copy Title: Land Use and Growth Impacts from Highway Capacity Increases Author: Sanchez, Erik J Year: 2000 This analysis examined the historical relationship between land use changes and the location of capacity increasing highway projects in the State of Oregon from 1970 to 1990. Aerial photography for 18 cities was used to delineate the extent of urban development in each time period. A geographic information system (GIS) was used to assemble the data. Using this data, a logit regression model tested the significance of geographic variables such as proximity to highway projects, land use zoning classification, city size, and other spatial characteristics. The analytical methods used in this study incorporated a set of commonly used techniques to assess highway impacts on urban development patterns. The results suggest that for the 18 selected cities, the spatial measures performed well in predicting the location of urban development from 1970 to 1990. In addition, the results of the logit regression model indicated that controlling for other location factors, urban development had not clustered along state high project corridors as was suspected. Title: Land Use and Growth Impacts from Highway Capacity Increases Author: Sanchez, Erik J Year: 2000 This analysis examined the historical relationship between land use changes and the location of capacity increasing highway projects in the State of Oregon from 1970 to 1990. Aerial photography for 18 cities was used to delineate the extent of urban development in each time period. A geographic information system (GIS) was used to assemble the data. Using this data, a logit regression model tested the significance of geographic variables such as proximity to highway projects, land use zoning classification, city size, and other spatial characteristics. The analytical methods used in this study incorporated a set of commonly used techniques to assess highway impacts on urban development patterns. The results suggest that for the 18 selected cities, the spatial measures performed well in predicting the location of urban development from 1970 to 1990. In addition, the results of the logit regression model indicated that controlling for other location factors, urban development had not clustered along state high project corridors as was suspected. Close

• 23. [Article] Congestion and Emissions Mitigation: A Comparison of Capacity, Demand, and Efficiency Based Strategies

  Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation ...

  Citation × Citation Citation Abstract Copy Title: Congestion and Emissions Mitigation: A Comparison of Capacity, Demand, and Efficiency Based Strategies Author: Bigazzi, Alexander Y., Figliozzi, Miguel Year: 2012 Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and PM2.5 emissions, and on more heavily congested arterials. Advanced-efficiency vehicles with emissions rates that are less sensitive to congestion than conventional vehicles generate less emissions co-benefits from congestion mitigation. Title: Congestion and Emissions Mitigation: A Comparison of Capacity, Demand, and Efficiency Based Strategies Author: Bigazzi, Alexander Y., Figliozzi, Miguel Year: 2012 Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and PM2.5 emissions, and on more heavily congested arterials. Advanced-efficiency vehicles with emissions rates that are less sensitive to congestion than conventional vehicles generate less emissions co-benefits from congestion mitigation. Close

• 24. [Article] High Performance Prussian Blue Cathode for Nonaqueous Ca-ion Intercalation Battery

  Potassium iron hexacyanoferrate, or Prussian blue (PB), is investigated as a cathode material for nonaqueous divalent calcium ion batteries. PB is an attractive prospect due to its high specific capacity, ...

  Citation × Citation Citation Abstract Copy Title: High Performance Prussian Blue Cathode for Nonaqueous Ca-ion Intercalation Battery Author: Kuperman, Neal, Padigi, Prasanna, Goncher, Gary, Evans, David, Thiebes, Joseph, Solanki, Raj Year: 2017 Potassium iron hexacyanoferrate, or Prussian blue (PB), is investigated as a cathode material for nonaqueous divalent calcium ion batteries. PB is an attractive prospect due to its high specific capacity, nontoxicity, low cost, and simple synthesis. Charge/discharge performances are examined at current densities of 23 mAg−1, 45 mAg−1, 90 mAg−1, and 125 mAg−1 that produced reversible specific capacities ranging from 150 mAhg−1 (at 23 mAg−1 current density) to over 120 mAhg−1 (at 125 mAg−1 current density). These are the highest storage capacities to date for a divalent calcium ion cathode over extended period of charge/discharge cycling and are comparable in performance to monovalent intercalating ions. Title: High Performance Prussian Blue Cathode for Nonaqueous Ca-ion Intercalation Battery Author: Kuperman, Neal, Padigi, Prasanna, Goncher, Gary, Evans, David, Thiebes, Joseph, Solanki, Raj Year: 2017 Potassium iron hexacyanoferrate, or Prussian blue (PB), is investigated as a cathode material for nonaqueous divalent calcium ion batteries. PB is an attractive prospect due to its high specific capacity, nontoxicity, low cost, and simple synthesis. Charge/discharge performances are examined at current densities of 23 mAg−1, 45 mAg−1, 90 mAg−1, and 125 mAg−1 that produced reversible specific capacities ranging from 150 mAhg−1 (at 23 mAg−1 current density) to over 120 mAhg−1 (at 125 mAg−1 current density). These are the highest storage capacities to date for a divalent calcium ion cathode over extended period of charge/discharge cycling and are comparable in performance to monovalent intercalating ions. Close

• 25. [Article] Postpollination Discrimination Between Self and Outcross Pollen Covaries with the Mating System of a Self-Compatible Flowering Plant

  Premise of the Study: Variation in the mating system of hermaphroditic plant populations is determined by interactions between genetic and environmental factors operating via both pre- and postmating processes. ...

  Citation × Citation Citation Abstract Copy Title: Postpollination Discrimination Between Self and Outcross Pollen Covaries with the Mating System of a Self-Compatible Flowering Plant Author: Cruzan, Mitchell B., Barrett, Spencer C. H. Year: 2016 Premise of the Study: Variation in the mating system of hermaphroditic plant populations is determined by interactions between genetic and environmental factors operating via both pre- and postmating processes. Models predicting the maintenance of intermediate outcrossing rates in animal-pollinated plants often assume that the mating system is primarily controlled by floral morphology and pollinator availability, but rarely has the influence of postpollination processes on variation in outcrossing been examined. Methods: We investigated the influence of stylar discrimination between illegitimate and legitimate pollen-tube growth and the pollen-load capacity of stigmas on mating-system variation in the annual, tristylous species Eichhornia paniculata using controlled crosses and genetic markers. This species exhibits an exceptionally broad range of outcrossing rates in natural populations. Key Results: There was significant variation among populations in the pollen-load capacity of stigmas and the ability of styles to discriminate between illegitimate vs. legitimate pollen. There was strong correspondence between stylar-discrimination ability and variation in outcrossing rate among populations and style morphs. The combination of stigmatic pollen-load capacity and stylar discrimination explained more than 80% of the variation in outcrossing rates among populations. Conclusions: The finding that stigmatic pollen-load capacity and stylar-discrimination ability contributed significantly to explaining the wide range of outcrossing rates in E. paniculata suggests that postpollination mechanisms play an important role in governing mating patterns in this species. The difference in levels of stylar discrimination between outcrossing and selfing populations may reflect a trade-off between selection for increased outcrossing and greater reproductive assurance. Title: Postpollination Discrimination Between Self and Outcross Pollen Covaries with the Mating System of a Self-Compatible Flowering Plant Author: Cruzan, Mitchell B., Barrett, Spencer C. H. Year: 2016 Premise of the Study: Variation in the mating system of hermaphroditic plant populations is determined by interactions between genetic and environmental factors operating via both pre- and postmating processes. Models predicting the maintenance of intermediate outcrossing rates in animal-pollinated plants often assume that the mating system is primarily controlled by floral morphology and pollinator availability, but rarely has the influence of postpollination processes on variation in outcrossing been examined. Methods: We investigated the influence of stylar discrimination between illegitimate and legitimate pollen-tube growth and the pollen-load capacity of stigmas on mating-system variation in the annual, tristylous species Eichhornia paniculata using controlled crosses and genetic markers. This species exhibits an exceptionally broad range of outcrossing rates in natural populations. Key Results: There was significant variation among populations in the pollen-load capacity of stigmas and the ability of styles to discriminate between illegitimate vs. legitimate pollen. There was strong correspondence between stylar-discrimination ability and variation in outcrossing rate among populations and style morphs. The combination of stigmatic pollen-load capacity and stylar discrimination explained more than 80% of the variation in outcrossing rates among populations. Conclusions: The finding that stigmatic pollen-load capacity and stylar-discrimination ability contributed significantly to explaining the wide range of outcrossing rates in E. paniculata suggests that postpollination mechanisms play an important role in governing mating patterns in this species. The difference in levels of stylar discrimination between outcrossing and selfing populations may reflect a trade-off between selection for increased outcrossing and greater reproductive assurance. Close

• 26. [Article] Similarity of Nutrient Uptake and Root Dimensions of Engelmann Spruce and Subalpine Fir at Two Contrasting Sites in Colorado

  Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this ...

  Citation × Citation Citation Abstract Copy Title: Similarity of Nutrient Uptake and Root Dimensions of Engelmann Spruce and Subalpine Fir at Two Contrasting Sites in Colorado Author: Lucash, Melissa S., Yanai, Ruth D., McFarlane, Karis J., Kulpa, Sarah E., Wood, Dustin M. Year: 2009 Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96h, and solutions were analyzed for ammonium, nitrate, calcium, magnesium, and potassium. Surprisingly, the two species were indistinguishable in nutrient uptake within site for all nutrients (P >0.25), but uptake rates differed by site. In general, nutrient uptake was higher at Fraser (P =0.01, 0.15, 0.03, and 0.18 for NH4+, NO3−, Ca2+, and K+, respectively), which is west of the Continental Divide and has lower atmospheric deposition of N than Loch Vale. Mean uptake rates by site for ambient solution concentrations were , , , and at Loch Vale, and , , , and at Fraser. The importance of site conditions in determining uptake capacity should not be overlooked when parameterizing nutrient uptake models. We also characterized the root morphology of these two species and compared them to other tree species we have measured at various sites in the northeastern USA. Engelmann spruce and subalpine fir were indistinguishable in specific root length and diameter distribution, while most of the other 10 species had statistically distinct diameter distributions across five diameter classes. Title: Similarity of Nutrient Uptake and Root Dimensions of Engelmann Spruce and Subalpine Fir at Two Contrasting Sites in Colorado Author: Lucash, Melissa S., Yanai, Ruth D., McFarlane, Karis J., Kulpa, Sarah E., Wood, Dustin M. Year: 2009 Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96h, and solutions were analyzed for ammonium, nitrate, calcium, magnesium, and potassium. Surprisingly, the two species were indistinguishable in nutrient uptake within site for all nutrients (P >0.25), but uptake rates differed by site. In general, nutrient uptake was higher at Fraser (P =0.01, 0.15, 0.03, and 0.18 for NH4+, NO3−, Ca2+, and K+, respectively), which is west of the Continental Divide and has lower atmospheric deposition of N than Loch Vale. Mean uptake rates by site for ambient solution concentrations were , , , and at Loch Vale, and , , , and at Fraser. The importance of site conditions in determining uptake capacity should not be overlooked when parameterizing nutrient uptake models. We also characterized the root morphology of these two species and compared them to other tree species we have measured at various sites in the northeastern USA. Engelmann spruce and subalpine fir were indistinguishable in specific root length and diameter distribution, while most of the other 10 species had statistically distinct diameter distributions across five diameter classes. Close

• 27. [Article] Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface Bonded Carbon Fiber-Reinforced Polymer

  This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for ...

  Citation × Citation Citation Abstract Copy Title: Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface Bonded Carbon Fiber-Reinforced Polymer Author: Higgins, Christopher, Dawson, Matthew R., Mitchell, Mikal M., Sopal, Gautam, Senturk, A. Ekin Year: 2009 This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort included determining the role of freeze-thaw, moisture, and fatigue on structural performance and developing analytical design procedures that account for durability. The results showed that moisture infiltration behind the CFRP, combined with freeze-thaw, was critical in reducing shear panel stiffness and shear capacity. Long-term moisture exposure alone produced only a minor decrease in shear capacity. Freeze-thaw, combined with fatigue, had little effect on shear capacity if water infiltration was minimized. Fatigue caused some debonding, but the debonding was not significant enough to affect capacity. Use of ACI-318 with ACI 440 provided conservative predicted shear strengths after environmental exposure. However, the ACI approach did not provide uniform levels of safety because the observed conservatism was built into the prediction for the unstrengthened base specimens but not for the CFRP contribution. Consequently, a recommendation of the research is to apply the environmental exposure factor at the final design step to limit the effective CFRP stress/strain. For locations with very large numbers of wet freeze-thaw cycles and extended exposure to continuous moisture, the environmental reduction factors should be reduced even further. To better predict the CFRP bond strength demands that can occur due to shear-moment interaction, a further check of the design should be made beyond those required by ACI-440. Title: Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface Bonded Carbon Fiber-Reinforced Polymer Author: Higgins, Christopher, Dawson, Matthew R., Mitchell, Mikal M., Sopal, Gautam, Senturk, A. Ekin Year: 2009 This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort included determining the role of freeze-thaw, moisture, and fatigue on structural performance and developing analytical design procedures that account for durability. The results showed that moisture infiltration behind the CFRP, combined with freeze-thaw, was critical in reducing shear panel stiffness and shear capacity. Long-term moisture exposure alone produced only a minor decrease in shear capacity. Freeze-thaw, combined with fatigue, had little effect on shear capacity if water infiltration was minimized. Fatigue caused some debonding, but the debonding was not significant enough to affect capacity. Use of ACI-318 with ACI 440 provided conservative predicted shear strengths after environmental exposure. However, the ACI approach did not provide uniform levels of safety because the observed conservatism was built into the prediction for the unstrengthened base specimens but not for the CFRP contribution. Consequently, a recommendation of the research is to apply the environmental exposure factor at the final design step to limit the effective CFRP stress/strain. For locations with very large numbers of wet freeze-thaw cycles and extended exposure to continuous moisture, the environmental reduction factors should be reduced even further. To better predict the CFRP bond strength demands that can occur due to shear-moment interaction, a further check of the design should be made beyond those required by ACI-440. Close

• 28. [Article] Planning for a Semiconductor Ramp: Capacity and Staffing

  ABC, a semiconductor manufacturing company has the good fortune to be starting a very strong manufacturing ramp for its biggest money making product line. In order for the ramp to succeed, they have to ...

  Citation × Citation Citation Abstract Copy Title: Planning for a Semiconductor Ramp: Capacity and Staffing Author: Varma, Sumir Year: 2015 ABC, a semiconductor manufacturing company has the good fortune to be starting a very strong manufacturing ramp for its biggest money making product line. In order for the ramp to succeed, they have to ensure that at the four main production steps where all the WIP goes through, there is enough capacity to run production as the ramp progresses through the wafer start nodes outlined, in a potentially optimized way, and the new tools purchased for this purpose are staffed adequately. However, based on the definition of the model utilized, the latter part of the project was changed substantially in practice. Title: Planning for a Semiconductor Ramp: Capacity and Staffing Author: Varma, Sumir Year: 2015 ABC, a semiconductor manufacturing company has the good fortune to be starting a very strong manufacturing ramp for its biggest money making product line. In order for the ramp to succeed, they have to ensure that at the four main production steps where all the WIP goes through, there is enough capacity to run production as the ramp progresses through the wafer start nodes outlined, in a potentially optimized way, and the new tools purchased for this purpose are staffed adequately. However, based on the definition of the model utilized, the latter part of the project was changed substantially in practice. Close

• 29. [Article] Determination of an Annual Production Plan for a Multiplant

  A linear programming model is developed to maximize profits of an international corporation which faces a problem of scheduling available resources to produce a more competitive product. The company produces ...

  Citation × Citation Citation Abstract Copy Title: Determination of an Annual Production Plan for a Multiplant Author: Cross, Darrell K., Montoya, Diego, Parmentor, Ron, Rakine, Easton, Tiu, Kian Hun Year: 1988 A linear programming model is developed to maximize profits of an international corporation which faces a problem of scheduling available resources to produce a more competitive product. The company produces mobile industrial equipment and has manufacturing plants in Europe and the U.S. It serves the market in both areas. A plant of limited capacity is available in each area. The company prefers to use existing plants to exploit unused capacity, rather than to build a new factory. The alternatives are to dual-source the product, or choose a plant for worldwide distribution. Title: Determination of an Annual Production Plan for a Multiplant Author: Cross, Darrell K., Montoya, Diego, Parmentor, Ron, Rakine, Easton, Tiu, Kian Hun Year: 1988 A linear programming model is developed to maximize profits of an international corporation which faces a problem of scheduling available resources to produce a more competitive product. The company produces mobile industrial equipment and has manufacturing plants in Europe and the U.S. It serves the market in both areas. A plant of limited capacity is available in each area. The company prefers to use existing plants to exploit unused capacity, rather than to build a new factory. The alternatives are to dual-source the product, or choose a plant for worldwide distribution. Close

• 30. [Article] Probabilistic Determination of Failure Load Capacity Variations for Lattice Type Structures Based on Yield Strength Variations including Nonlinear Post-Buckling Member Performance

  With the attempt to achieve the optimum in analysis and design, the technological global knowledge base grows more and more. Engineers all over the world continuously modify and innovate existing analysis ...

  Citation × Citation Citation Abstract Copy Title: Probabilistic Determination of Failure Load Capacity Variations for Lattice Type Structures Based on Yield Strength Variations including Nonlinear Post-Buckling Member Performance Author: Bathon, Leander Anton Year: 1992 With the attempt to achieve the optimum in analysis and design, the technological global knowledge base grows more and more. Engineers all over the world continuously modify and innovate existing analysis methods and design procedures to perform the same task more efficiently and with better results. In the field of complex structural analysis many researchers pursue this challenging task. The complexity of a lattice type structure is caused by numerous parameters: the nonlinear member performance of the material, the statistical variation of member load capacities, the highly indeterminate structural composition, etc. In order to achieve a simulation approach which represents the real world problem more accurately, it is necessary to develop technologies which include these parameters in the analysis. One of the new technologies is the first order nonlinear analysis of lattice type structures including the after failure response of individual members. Such an analysis is able to predict the failure behavior of a structural system under ultimate loads more accurately than the traditionally used linear elastic analysis or a classical first order nonlinear analysis. It is an analysis procedure which can more accurately evaluate the limit-state of a structural system. The Probability Based Analysis (PBA) is a new technology. It provides the user with a tool to analyze structural systems based on statistical variations in member capacities. Current analysis techniques have shown that structural failure is sensitive to member capacity. The combination of probability based analysis and the limit-state analysis will give the engineer the capability to establish a failure load distribution based on the limit-state capacity of the structure. This failure load distribution which gives statistical properties such as mean and variance improves the engineering judgment. The mean shows the expected value or the mathematical expectation of the failure load. The variance is a tool to measure the variability of the failure load distribution. Based on a certain load case, a small variance will indicate that a few members cause the tower failure over and over again; the design is unbalanced. A large variance will indicate that many different members caused the tower failure. The failure load distribution helps in comparing and evaluating actual test results versus analytical results by locating an actual test among the possible failure loads of a tower series. Additionally, the failure load distribution allows the engineer to calculate exclusion limits which are a measure of the probability of success, or conversely the probability of failure for a given load condition. The exclusion limit allows engineers to redefine their judgement on safety and usability of transmission towers. Existing transmission towers can be reanalyzed using this PBA and upgraded based on a given exclusion limit for a chosen tower capacity increase according to the elastic analysis from which the tower was designed. New transmission towers can be analyzed based on the actual yield strength data and their nonlinear member performances. Based on this innovative analysis the engineer is able to improve tower design by using a tool which represents the real world behavior of steel transmission towers more accurately. Consequently it will improve structural safety and reduce cost. Title: Probabilistic Determination of Failure Load Capacity Variations for Lattice Type Structures Based on Yield Strength Variations including Nonlinear Post-Buckling Member Performance Author: Bathon, Leander Anton Year: 1992 With the attempt to achieve the optimum in analysis and design, the technological global knowledge base grows more and more. Engineers all over the world continuously modify and innovate existing analysis methods and design procedures to perform the same task more efficiently and with better results. In the field of complex structural analysis many researchers pursue this challenging task. The complexity of a lattice type structure is caused by numerous parameters: the nonlinear member performance of the material, the statistical variation of member load capacities, the highly indeterminate structural composition, etc. In order to achieve a simulation approach which represents the real world problem more accurately, it is necessary to develop technologies which include these parameters in the analysis. One of the new technologies is the first order nonlinear analysis of lattice type structures including the after failure response of individual members. Such an analysis is able to predict the failure behavior of a structural system under ultimate loads more accurately than the traditionally used linear elastic analysis or a classical first order nonlinear analysis. It is an analysis procedure which can more accurately evaluate the limit-state of a structural system. The Probability Based Analysis (PBA) is a new technology. It provides the user with a tool to analyze structural systems based on statistical variations in member capacities. Current analysis techniques have shown that structural failure is sensitive to member capacity. The combination of probability based analysis and the limit-state analysis will give the engineer the capability to establish a failure load distribution based on the limit-state capacity of the structure. This failure load distribution which gives statistical properties such as mean and variance improves the engineering judgment. The mean shows the expected value or the mathematical expectation of the failure load. The variance is a tool to measure the variability of the failure load distribution. Based on a certain load case, a small variance will indicate that a few members cause the tower failure over and over again; the design is unbalanced. A large variance will indicate that many different members caused the tower failure. The failure load distribution helps in comparing and evaluating actual test results versus analytical results by locating an actual test among the possible failure loads of a tower series. Additionally, the failure load distribution allows the engineer to calculate exclusion limits which are a measure of the probability of success, or conversely the probability of failure for a given load condition. The exclusion limit allows engineers to redefine their judgement on safety and usability of transmission towers. Existing transmission towers can be reanalyzed using this PBA and upgraded based on a given exclusion limit for a chosen tower capacity increase according to the elastic analysis from which the tower was designed. New transmission towers can be analyzed based on the actual yield strength data and their nonlinear member performances. Based on this innovative analysis the engineer is able to improve tower design by using a tool which represents the real world behavior of steel transmission towers more accurately. Consequently it will improve structural safety and reduce cost. Close