Op 9 juni 2010 werd bij de Hanzehogeschool Groningen een seminar georganiseerd met het thema IT offshoring en het MKB onder de titel “The Hanze-India Connection”. In dit rapport wordt verslag gedaan van de presentaties en daaropvolgende discussies. REP-10-01.
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Post-earthquake structural damage shows that out-of-plane wall collapse is one of the most prevalent failure mechanisms in unreinforced masonry (URM) buildings. This issue is particularly critical in Groningen, a province located in the northern part of the Netherlands, where low-intensity ground shaking has occurred since 1991 due to gas extraction. The majority of buildings in this area are constructed using URM and were not designed to withstand earthquakes, as the area had never been affected by tectonic seismic activity before. Hence, the assessment of URM buildings in the Groningen province has become of high relevance.Out-of-plane failure mechanisms in brick masonry structures often stem from poor wall-to-wall, wall-to-floor or wall-to-roof connections that provide insufficient restraint and boundary conditions. Therefore, studying the mechanical behaviour of such connections is of prime importance for understanding and preventing damages and collapses in URM structures. Specifically, buildings with double-leaf cavity walls constitute a large portion of the building stock in the Groningen area. The connections of the leaves in cavity walls, which consist of metallic ties, are expected to play an important role. Regarding the wall-to-floor connections, the traditional way for URM structures in Dutch construction practice is either a simple masonry pocket connection or a hook anchor as-built connection, which are expected to be vulnerable to out-of-plane excitation. However, until now, little research has been carried out to characterise the seismic behaviour of connections between structural elements in traditional Dutch construction practice.This thesis investigates the seismic behaviour of two types of connections: wall-to-wall connections between cavity wall leaves and wall-to-floor connections between the masonry cavity wall and timber diaphragm, commonly found in traditional houses in the Groningen area. The research is divided into three phases: (1) inventory of existing buildings and connections in the Groningen area, (2) performance of experimental tests, and (3) proposal and validation of numerical and mechanical models. The thesis explores the three phases as follows:(i) An inventory of connections within URM buildings in the Groningen area is established. The inventory includes URM buildings of Groningen based on construction material, lateral load-resisting system, floor system, number of storeys, and connection details. Specific focus is given to the wall-to-wall and wall-to-floor connections in each URM building. The thickness of cavity wall leaves, the air gap between the leaves and the size and spacing of timber joists are key aspects of the inventory.(ii) Experimental tests are performed on the most common connection typologies identified in the inventory. This phase consists of two distinct experimental campaigns:o The first experimental campaign took place at the laboratory of the Delft University of Technology to provide a comprehensive characterisation of the axial behaviour of traditional metal tie connections in cavity walls. The campaign included a wide range of variations, such as two embedment lengths, four pre-compression levels, two different tie geometries, and five different testing protocols, including both monotonic and cyclic loading. The experimental results showed that the capacity of the wall tie connection is strongly influenced by the embedment length and the tie geometry, whereas the applied pre-compression and the loading rate do not have a significant influence.o The second experimental campaign has been carried out at the laboratory of the Hanze University of Applied Sciences to characterise the seismic behaviour of timber joist-masonry cavity wall connections, reproducing both as-built and strengthened conditions. Twenty-two unreinforced masonry wallets were tested, with different configurations, including two tie distributions, two pre-compression levels, two different as-built connections, and two different strengthening solutions. The experimental results highlighted the importance of cohesion and friction between joist and masonry since the type of failure mechanism (sliding of the joist or rocking failure of the masonry wallet) depends on the value of these two parameters. Additionally, the interaction between the joist and the wallet and the uplift of the latter activated due to rocking led to an arching effect that increased friction at the interface between the joist and the masonry. Consequently, the arching effect enhanced the force capacity of the connection.(iii) Mechanical and numerical models are proposed and validated against the performed experiments or other benchmarks. Mechanical and numerical models for the cavity wall tie and mechanical models for the timber joist-masonry connections were developed and verified by the experimental results to predict the failure mode and the strength capacity of the examined connections in URM buildings.o The mechanical model for the cavity wall tie connections considers six possible failures, namely tie failure, cone break-out failure, pull-out failure, buckling failure, piercing failure and punching failure. The mechanical model is able to capture the mean peak force and the failure mode obtained from the tests. After being calibrated against the available experiments, the proposed mechanical model is used to predict the performance of untested configurations by means of parametric analyses, including higher strength of mortar for calcium silicate brick masonry, different cavity depth, different tie embedment depth, and the use of solid bricks in place of perforated clay bricks.o The results of the experimental campaign on cavity wall ties were also utilised to calibrate a hysteretic numerical model representing the cyclic axial response of cavity wall tie connections. The proposed model uses zero-length elements implemented in OpenSees with the Pinching4 constitutive model to account for the compression-tension cyclic behaviour of the ties. The numerical model is able to capture important aspects of the tie response, such as strength degradation, unloading stiffness degradation, and pinching behaviour. The mechanical and numerical modelling approach can be easily adopted by practitioner engineers seeking to model the wall ties more accurately when assessing URM structures against earthquakes.o The mechanical model of timber-masonry connections examines two different failure modes: joist-sliding failure mode, including joist-to-wall interaction and rocking failure mode due to joist movement. Both mechanical models have been validated against the outcomes of the experimental campaigns conducted on the corresponding connections. The mechanical model is able to estimate each contribution of the studied mechanism. Structural engineers can use the mechanical model to predict the capacity of the connection for the studied failure modes.This research study can contribute to a better understanding of typical Groningen houses in terms of identifying the most common connections used at wall-to-wall and wall-to-floor connections in cavity walls, characterising the identified connections and proposing mechanical models for the studied connections.
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This study used historical data from a Park & Ride facility in Amsterdam to build a validated computer (Python) model to optimize battery and grid connection sizing. The case study modelled is equipped with 8 EV chargers (16 connections), an on-site supplementary battery, and a limited capacity grid connection. This model was then used to optimize the battery energy storage capacity and grid connection capacity for minimal annualized investment, using a future proof monthly load profile. A variety of battery control strategies were simulated using both the optimal system sizing and the current system sizing. The results were compared and a recommended control strategy presented, considering a number of performance metrics.
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Green Sustainable Airport (GSA), an Interreg IVB project that is part of the North Sea Region Program, is an initiative of Groningen Airport Eelde (GAE). One of the goals of the GSA project is: The development and testing of sustainable and innovative applications that contribute to a more sustainable exploitation and increased accessibility of all partner airports. Currently a lot of research in the field of autonomous vehicles is carried out globally. In this research, named the “Flying Carpet”, the feasibility of using autonomous vehicles for passenger transfer between a future P+R facility at Glimmen and Groningen Airport Eelde is examined.Feasibility is researched on a technical, juridical and economic level. Implementing the proposed connection seems juridically feasible. -The juridical feasibility cannot be guaranteed, because it is a new situation whereby involved parties need to present a definitive answer, which at this stage is not possible. -Realizing the proposed concept has been indicated by the involved companies to be technically feasible, given that additional (existing) technologies will still need to be implemented. From a financial point of view, implementing an AGV connection is not recommendable. -The investment costs per transported passenger will be high, mainly because the transfer demand throughout a given day only has a few, if not just one, peak during arrival or departure of a flight. Therefore, choosing the AGV connection option should not be based on a financial point of view, but instead on gaining non-tangible assets in favour of GSA and GAE.
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This study presents a model-based analysis of the groundconnectivity performance of the future Santa Lucia-Mexico City multi-airport system. The plan of the currentgovernment is to connect the two airports by a dedicatedline, either by bus or other transport so that passengersand airlines can get the benefit of a coordinatedoperation. Performance indicators such as minimumconnecting time, vehicle utilization and passengerwaiting time are used to evaluate the future performance.Results reveal that when all passengers are allowed to usethe connection, a big number of vehicles are required forproviding a good level of service while in the case of arestricted use to only transfer passengers the operationwith Bus would have a good performance.
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The lack of in-depth understanding of the seismic behavior and ductility of precast concrete structures makes it difficult to reach to ductility demand which could be exhibited during an earthquake. The limitations are mainly related to the beam-to-column connections as the main load transfer paths. Two distinct exterior beam-column connections made of normal-strength concrete are investigated experimentally. Both dry and wet type installment techniques are used in the industrial type joints while the residential type joints are wet connections. The specimens are subjected cyclic displacement reversals in order to obtain information on strength, stiffness and ductility characteristics of the connection details. The preliminary design of the joints has been updated during the tests based on the damages observed, thus a set of improved specimens have also been built and tested, and a relatively better performance is obtained expectedly. The industrial and residential types of connections showed stable load-displacement cycles with high energy dissipation up to structural drift of 2%, though a significant level of pinching and deterioration of the critical section have occurred at around 3% drift level. The tested specimens have been numerically modeled to calibrate the analytical tools, and a satisfactory approximation has been obtained between experimental and numerical results.
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The ever-increasing electrification of society has been a cause of utility grid issues in many regions around the world. With the increased adoption of electric vehicles (EVs) in the Netherlands, many new charge points (CPs) are required. A common installation practice of CPs is to group multiple CPs together on a single grid connection, the so-called charging hub. To further ensure EVs are adequately charged, various control strategies can be employed, or a stationary battery can be connected to this network. A pilot project in Amsterdam was used as a case study to validate the Python model developed in this study using the measured data. This paper presents an optimisation of the battery energy storage capacity and the grid connection capacity for such a P&R-based charging hub with various load profiles and various battery system costs. A variety of battery control strategies were simulated using both the optimal system sizing and the case study sizing. A recommendation for a control strategy is proposed.
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KLM Royal Dutch Airlines has been a forerunner of the airline industry since 1919. As the oldest operating airline to date, the company aims to become innovators of today. This paper proposes an addition to the KLM transformation projects: Moving Your World, The Digital Transformation, and The KLM Real Estate Vision. This addition is a concept for ‘The Winning Way of Working,’ which aims to create a holistic workplace design; one where KLM employees are able to experience flexible and customizable environments, disconnection between colleagues and locations is reduced, and health benefits of vegetation in work environments are promoted.
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This study is the first to systematically and quantitatively explore the factors that determine the length of charging sessions at public charging stations for electric vehicles in urban areas, with particular emphasis placed on the combined parking- and charging-related determinants of connection times. We use a unique and large data set – containing information concerning 3.7 million charging sessions of 84,000 (i.e., 70% of) Dutch EV-users – in which both private users and taxi and car sharing vehicles are included; thus representing a large variation in charging duration behavior. Using multinomial logistic regression techniques, we identify key factors explaining heterogeneity in charging duration behavior across charging stations. We show how these explanatory variables can be used to predict EV-charging behavior in urban areas and we derive preliminary implications for policy-makers and planners who aim to optimize types and size of charging infrastructure.
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Het overkomt elke adviseur de laatste tijd. De klant wil ‘een totale web virale campagne’ die alle communicatieproblemen ineens verleden tijd maakt. Lekker gemaakt door stapels boeken en publicaties gebaseerd op slechts een paar succesvolle cases. Hogeschool Utrecht deed het afgelopen jaar onderzoek in opdracht van Creative Connection, een Utrechtse groep creatieve bedrijven, naar de succesfactoren van de inzet van social media bij communicatieprojecten. De komende weken doen we op Frankwatching verslag van de resultaten en lichten we een tipje van de sluier over het vervolgonderzoek waar we op dit moment mee bezig zijn. Vandaag deel 1: de doelstellingen.
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