The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
I.a. Saleh - One of the best experts on this subject based on the ideXlab platform.
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local design Testing and manufacturing of small mixed airfoil wind turbine blades of glass fiber reinforced plastics part ii manufacturing of the blade and rotor
Energy Conversion and Management, 2000Co-Authors: S.m. Habali, I.a. SalehAbstract:Wind energy has attracted a great deal of attention in recent years in Jordan as one of the possible alternative renewable energy resources. Almost of the local research and development activities in this field were directed to explore, develop, and optimal utilization of energy systems. The time has come to establish a link between local scientific (academic) work and local industries to produce a usable technology which will increase the local share in an inevitably emerging wind energy industry in Jordan. To achieve this goal, a well founded manufacturing base is required. The most important component of a Wind Energy Converter is the rotor. The efficiency of a rotor is characterized by its profile (airfoil section) and the corresponding aerodynamic design. A selection procedure of airfoil section and the aerodynamic design of the blade for a small wind turbine are discussed and implemented in this paper (Part I). It is found that for small blades up to 5 m long, two different air foils mixed at the outer third of the span will be sufficient and demonstrated good strength and aerodynamic characteristics. As a composite material, the Glass Fiber Reinforced Plastic was used in designing the rotor blade. This rotor was then installed on 15 kW grid-connected-pitch-controlled machine. A static Proof Load Test indicated that this blade could withstand Loads ten times the normal working thrust, and a field performance Test showed that the rotor blade has a 41.2% measured average power coefficient.
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Design and Testing of small mixed airfoil wind turbine blades
Renewable Energy, 1995Co-Authors: S.m. Habali, I.a. SalehAbstract:The design and selection procedure of airfoil sections for small wind turbine blades is discussed and implemented in this paper. It is found that for blades up to 5 m long, two different airfoils mixed at the outer third of the span will be sufficient and have demonstrated good strength and aerodynamic characteristics. The rotorblade design was executed using glassfiber reinforced plastic and then installed on a 15 kW grid-connected-pitch-controlled machine. A static Proof-Load Test indicated that the blade could withstand Loads 10 times the normal working thrust, and a field performance Test showed that the rotorblade has a 41.2% measured average power coefficient.
S.m. Habali - One of the best experts on this subject based on the ideXlab platform.
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local design Testing and manufacturing of small mixed airfoil wind turbine blades of glass fiber reinforced plastics part ii manufacturing of the blade and rotor
Energy Conversion and Management, 2000Co-Authors: S.m. Habali, I.a. SalehAbstract:Wind energy has attracted a great deal of attention in recent years in Jordan as one of the possible alternative renewable energy resources. Almost of the local research and development activities in this field were directed to explore, develop, and optimal utilization of energy systems. The time has come to establish a link between local scientific (academic) work and local industries to produce a usable technology which will increase the local share in an inevitably emerging wind energy industry in Jordan. To achieve this goal, a well founded manufacturing base is required. The most important component of a Wind Energy Converter is the rotor. The efficiency of a rotor is characterized by its profile (airfoil section) and the corresponding aerodynamic design. A selection procedure of airfoil section and the aerodynamic design of the blade for a small wind turbine are discussed and implemented in this paper (Part I). It is found that for small blades up to 5 m long, two different air foils mixed at the outer third of the span will be sufficient and demonstrated good strength and aerodynamic characteristics. As a composite material, the Glass Fiber Reinforced Plastic was used in designing the rotor blade. This rotor was then installed on 15 kW grid-connected-pitch-controlled machine. A static Proof Load Test indicated that this blade could withstand Loads ten times the normal working thrust, and a field performance Test showed that the rotor blade has a 41.2% measured average power coefficient.
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Design and Testing of small mixed airfoil wind turbine blades
Renewable Energy, 1995Co-Authors: S.m. Habali, I.a. SalehAbstract:The design and selection procedure of airfoil sections for small wind turbine blades is discussed and implemented in this paper. It is found that for blades up to 5 m long, two different airfoils mixed at the outer third of the span will be sufficient and have demonstrated good strength and aerodynamic characteristics. The rotorblade design was executed using glassfiber reinforced plastic and then installed on a 15 kW grid-connected-pitch-controlled machine. A static Proof-Load Test indicated that the blade could withstand Loads 10 times the normal working thrust, and a field performance Test showed that the rotorblade has a 41.2% measured average power coefficient.
Eva O L Lantsoght - One of the best experts on this subject based on the ideXlab platform.
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Proof Load Testing of reinforced concrete slab bridges in the Netherlands
2020Co-Authors: Eva O L Lantsoght, C. Van Der Veen, A. De Boer, Da Dick HordijkAbstract:The bridges built during the development of the Dutch road network after the Second World War are reaching their originally devised service life. A large subset of the Dutch bridge stock consists of reinforced concrete slab bridges. This bridge type often rates insufficient according to the recently introduced Eurocodes. Therefore, more suitable methods are developed to assess reinforced concrete slab bridges to help transportation officials make informed decisions about the safety and remaining life of the existing bridges. If information about a bridge is lacking, if the reduction in structural capacity caused by material degradation is unknown, or if an assessment shows insufficient capacity but additional capacity can be expected, a bridge might be suitable for a field Test. A Proof Load Test demonstrates that a given bridge can carry a certain Load level. In the Netherlands, a number of existing reinforced concrete slab bridges have been Proof Loaded, and one bridge has been Tested to collapse. Bridges with and without material damage were Tested. These bridges were heavily instrumented, in order to closely monitor the behavior of the bridge. Critical positions for bending moment and shear were studied. Based on the Proof Load Tests that were carried out over the past years, a set of recommendations for the systematic preparation, execution, and analysis of Proof Load Test results is compiled. These recommendations will ultimately form the basis of the guideline for Proof Load Testing for the Netherlands, which is currently under development.
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Proof Load Testing of reinforced concrete bridges: Experience from a program of Testing in the Netherlands
2020Co-Authors: Eva O L LantsoghtAbstract:For existing bridges with large uncertainties, analytical methods have limitations. Therefore, to reduce these uncertainties, field Testing of a bridge can be used. A type of such a field Test is a Proof Load Test, in which a Load equivalent to the factored live Load is applied. If the bridge can carry this Load without signs of distress, the Proof Load Test is successful, and it has been shown experimentally that the bridge fulfils the code requirements. It should be understood that this method for assessment is different from the diagnostic Load Tests that are carried out in Ecuador prior to opening a bridge. The Loads used for Proof Load Tests are significantly larger. Therefore, it is important to instrument the bridge for a Proof Load Test, and to evaluate during the Test that the Load does not result in permanent damage to the bridge. To research this topic, and to develop recommendations for Proof Load Tests, a series of Proof Load Tests and a collapse Test were carried out in the Netherlands. Additional laboratory Testing was carried out as well. Based on this information, recommendations for Proof Load Tests of reinforced concrete slab bridges have been developed for the failure modes of flexure and shear. In the German and North American guidelines for Load Testing, Load Testing for shear is not permitted. However, many existing bridges do not fulfil the requirements for shear upon assessment according to the current live Load models. Even though more experimental research is needed to develop Proof Load Testing for shear in a guideline or code for the Netherlands, the currently available research results already lead to interesting conclusions with regard to the behaviour of bridges Proof Load Tested in shear, and the required safety margin to avoid damage to the bridge.
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Stop criteria for Proof Load Tests verified with field and laboratory Testing of the Ruytenschildt Bridge
2020Co-Authors: Eva O L Lantsoght, Da Dick Hordijk, C. Van Der Veen, Yuguang Yang, Ane De BoerAbstract:As the existing bridge stock is aging, improved assessment methods such as Proof Load Testing become increasingly important. Proof Load Testing involves large Loads, and as such the risk for the structure and personnel can be significant. To capture the structural response, extensive measurements are applied to Proof Load Tests. Stop criteria, based on the measured quantities, are used to identify when further Loading in a Proof Load Test is not permitted. For Proof Load Testing of buildings, stop criteria are available in existing codes. For bridges, recently stop criteria based on laboratory Tests on beams reinforced with plain bars have been proposed. Subsequently, improved stop criteria were developed based on theoretical considerations for bending moment and shear. The stop criteria from the codes and the proposed stop criteria are compared to the results from field Testing to collapse on the Ruytenschildt Bridge, and to the results from laboratory Tests on beams sawn from the Ruytenschildt Bridge. This comparison shows that only a small change to the stop criteria derived from laboratory Testing is necessary. The experimental evidence strengthens the recommendation for using the proposed stop criteria in Proof Load Tests on bridges for bending moment, whereas further Testing to confirm the stop criteria for shear is necessary.
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Methodology for Proof Load Testing
2020Co-Authors: Eva O L LantsoghtAbstract:This chapter deals with the methodology for Proof Load Testing. All aspects of Proof Load Testing that are shared with other Load Testing methods have been discussed in Part II of Volume 12. In this chapter, the particularities of Proof Load Testing are discussed. These elements include the determination of the target Proof Load, the procedures followed during a Proof Load Test (Loading method, instrumentation, and stop criteria), and the post-processing of Proof Load Test data, including the assessment of a bridge after a Proof Load Test.
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Example of Proof Load Testing from Europe
2020Co-Authors: Eva O L Lantsoght, Rutger Koekkoek, Da Dick Hordijk, C. Van Der VeenAbstract:This chapter describes the Proof Load Testing of viaduct Zijlweg at a position that is critical for bending moment and at a position that is critical for shear. The viaduct Zijlweg has cracking caused by alkali-silica reaction, and the effect of material degradation on the capacity is uncertain. Therefore, the assessment of this viaduct was carried out with a Proof Load Test. This chapter details the preparation, execution, and evaluation of viaduct Zijlweg. The outcome of the Proof Load Test is, according to the currently used methods for Proof Load Testing, that the viaduct fulfills the code requirements, and that strengthening or posting is not required.
Ane De Boer - One of the best experts on this subject based on the ideXlab platform.
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Stop criteria for Proof Load Tests verified with field and laboratory Testing of the Ruytenschildt Bridge
2020Co-Authors: Eva O L Lantsoght, Da Dick Hordijk, C. Van Der Veen, Yuguang Yang, Ane De BoerAbstract:As the existing bridge stock is aging, improved assessment methods such as Proof Load Testing become increasingly important. Proof Load Testing involves large Loads, and as such the risk for the structure and personnel can be significant. To capture the structural response, extensive measurements are applied to Proof Load Tests. Stop criteria, based on the measured quantities, are used to identify when further Loading in a Proof Load Test is not permitted. For Proof Load Testing of buildings, stop criteria are available in existing codes. For bridges, recently stop criteria based on laboratory Tests on beams reinforced with plain bars have been proposed. Subsequently, improved stop criteria were developed based on theoretical considerations for bending moment and shear. The stop criteria from the codes and the proposed stop criteria are compared to the results from field Testing to collapse on the Ruytenschildt Bridge, and to the results from laboratory Tests on beams sawn from the Ruytenschildt Bridge. This comparison shows that only a small change to the stop criteria derived from laboratory Testing is necessary. The experimental evidence strengthens the recommendation for using the proposed stop criteria in Proof Load Tests on bridges for bending moment, whereas further Testing to confirm the stop criteria for shear is necessary.
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Optimizing Finite Element Models for Concrete Bridge Assessment With Proof Load Testing
Frontiers in Built Environment, 2019Co-Authors: Eva O L Lantsoght, Ane De Boer, C. Van Der Veen, Da Dick HordijkAbstract:Proof Load Testing of existing reinforced concrete bridges is becoming increasingly important as the current bridge stock is aging. In a Proof Load Test, a Load that corresponds to the factored live Load is applied to a bridge structure, to directly demonstrate that a bridge fulfills the code requirements. To optimize the procedures used in Proof Load Tests, it can be interesting to combine field Testing and finite element modeling. Finite element models can for example be used to assess a Tested structure after the Test when the critical position could not be Loaded. In this paper, the case of viaduct De Beek, a four-span reinforced concrete slab bridge, is studied. Upon assessment, it was found that the requirements for bending moment are not fulfilled for this structure. This viaduct was Proof Load Tested in the end span. However, the middle spans are the critical spans of this structure. The initial assessment of this viaduct was carried out with increasingly refined linear finite element models. To further study the behavior of this bridge, a non-linear finite element model is used. The data from the field Test (measured strains on the bottom of the concrete cross-section, as well as measured deflection profiles) are used to update the non-linear finite element model for the end span, and to improve the modeling and assessment of the critical middle spans of the structure. Similarly, an improved assessment based on a linear finite element model is carried out. The approaches shown for viaduct De Beek should be applied for other case studies before recommendations for practice can be formulated. Eventually, an optimized combination of field Testing and finite element modeling will result in an approach that potentially reduces the cost of field Testing.
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Stop Criteria for Flexure for Proof Load Testing of Reinforced Concrete Structures
Frontiers in Built Environment, 2019Co-Authors: Eva O L Lantsoght, Cor Van Der Veen, Da Dick Hordijk, Yuguang Yang, Ane De BoerAbstract:Existing bridges with large uncertainties can be assessed with a Proof Load Test. In a Proof Load Test, a Load representative of the factored live Load is applied to the bridge at the critical position. If the bridge can carry this Load without distress, the Proof Load Test shows experimentally that the bridge fulfills the requirements of the code. Because large Loads are applied during Proof Load Tests, the structure or element that is Tested needs to be carefully monitored during the Test. The monitored structural responses are interpreted in terms of stop criteria. Existing stop criteria for flexure in reinforced concrete can be extended with theoretical considerations. These proposed stop criteria are then verified with experimental results: reinforced concrete beams failing in flexure and Tested in the laboratory, a collapse Test on an existing reinforced concrete slab bridge that reached flexural distress, and the pilot Proof Load Tests that were carried out in the Netherlands and in which no distress was observed. The Tests in which failure was obtained are used to evaluate the margin of safety provided by the proposed stop criteria. The available pilot Proof Load Tests are analyzed to see if the proposed stop criteria are not overly conservative. The result of this comparison is that the stop criteria are never exceeded. Therefore, the proposed stop criteria can be used for Proof Load Tests for the failure mode of bending moment in reinforced concrete structures.
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pilot Proof Load Test on viaduct de beek case study
Journal of Bridge Engineering, 2017Co-Authors: Eva O L Lantsoght, Rutger Koekkoek, Cor Van Der Veen, D A Hordijk, Ane De BoerAbstract:For existing bridges, Proof-Load Testing can be a suitable assessment method. This paper addresses the evaluation of a posted reinforced concrete slab bridge over a highway through Proof-Load Testing, detailing the preparation, execution, and analysis of the Test. As the target Proof-Load and the required measurements for Proof-Load Testing currently are not well-defined in the existing codes, this pilot case was used to develop and evaluate proposed recommendations for Proof-Load Testing for a future guideline on Proof-Load Testing for the Netherlands. Moreover, the pilot Proof-Load Test is used to study the feasibility of Proof-Load Testing for both shear and flexure
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Development of recommendations for Proof Load Testing of reinforced concrete slab bridges
Engineering Structures, 2017Co-Authors: Eva O L Lantsoght, Cor Van Der Veen, Da Dick Hordijk, Ane De BoerAbstract:As the bridge stock in the Netherlands and Europe is ageing, various methods to analyze existing bridges are being studied. Proof Load Testing of bridges is an option to experimentally demonstrate that a given bridge can carry the prescribed live Loads. Based on extensive research on Proof Load Testing of reinforced concrete slab bridges carried out in the Netherlands, recommendations for Proof Load Testing of reinforced concrete slab bridges were developed. The recommendations for the preparation, execution, and post-processing of a Proof Load Test are summarized in this paper. The novelty of the recommendations is that Proof Load Testing for shear is studied, and that a proposal for stop criteria for shear and bending moment has been formulated. Further research on the shear behavior is necessary, after which the recommendations will be converted in guidelines for the industry.
Marija Docevska - One of the best experts on this subject based on the ideXlab platform.
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assessment of damaged timber structures using Proof Load Test experience from case studies
Construction and Building Materials, 2015Co-Authors: Toni Arangjelovski, Kiril Gramatikov, Marija DocevskaAbstract:Abstract In this paper assessment of damaged timber structures using Proof Load Test is given, which is mandatory according to Macedonian standards. Two types of structures were analyzed in the paper: Glued laminated timber structure, Cambered beam span of L = 24.00 m and Glued Laminated pedestrian timber bridge, two-hinged arch, span of L = 26.00 m plus two simple supported beams span of L = 12.5 m each. The results were also used for reliability verification to define partial safety factor for material for ultimate limit state and serviceability limit state, according to Eurocodes EN1990 and EN1995.
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Assessment of damaged timber structures using Proof Load Test – Experience from case studies
Construction and Building Materials, 2015Co-Authors: Toni Arangjelovski, Kiril Gramatikov, Marija DocevskaAbstract:Abstract In this paper assessment of damaged timber structures using Proof Load Test is given, which is mandatory according to Macedonian standards. Two types of structures were analyzed in the paper: Glued laminated timber structure, Cambered beam span of L = 24.00 m and Glued Laminated pedestrian timber bridge, two-hinged arch, span of L = 26.00 m plus two simple supported beams span of L = 12.5 m each. The results were also used for reliability verification to define partial safety factor for material for ultimate limit state and serviceability limit state, according to Eurocodes EN1990 and EN1995.
