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The last decade has seen a growing interest in cohesive zone models for fatigue applications. These cohesive zone models often suffer from a lack of generality and applying them typically requires calibrating a large number of model-specific parameters. To improve on these issues a new method has been proposed in this paper based on the Thick Level Set approach. In this concept, material degradation due to cyclic loading is the result of interaction between damage evolution and fracture mechanics. The Thick Level Set formulation has been extended to interface elements, in order to allow for separation of strain energy in the bulk and energy required for surface creation. Global fracture parameters, derived from a free energy description governing the interface elements, are used as input for the empirical crack growth rate relation (Paris’ equation). It must be emphasized that in contrast to existing fatigue models, the Thick Level Set approach does not require the definition of a damage evolution law. Instead, damage is updated automatically by a continuously moving damage front. It is shown that applicability is not limited to fatigue behavior of linear elastic materials; elastic-plastic materials such as steels can be analysed as well. The sensitivity of model parameters is investigated and discussed and the practical relevance is explored for standard test configurations.

Modeling the stochastic evolution of a large-scale fleet or network generally proves to be challenging. This difficulty may be compounded through complex relationships between various assets in the network. Although a great number of probabilistic graph-based models (e.g., Bayesian networks) have been developed recently to describe the behavior of single assets, one can find significantly fewer approaches addressing a fully integrated network. It is proposed an extension to the standard dynamic Bayesian network (DBN) by introducing an additional dimension for multiple elements. These elements are then linked through a set of covariates that translate the probabilistic dependencies. A Markov chain is utilized to model the elements and develop a distribution-free mathematical framework to parameterize the transition probabilities without previous data. This is achieved by borrowing from Cooke's method for structured expert judgment and also applied to the quantification of the covariate relationships. Some metrics are also presented for evaluating the sensitivity of information inserted into the covariate DBN where the focus is given on two specific types of configurations. The model is applied to a real-world example of steel bridge network in the Netherlands. Numerical examples highlight the inference mechanism and show the sensitivity of information inserted in various ways. It is shown that information is most valuable very early and decreases substantially over time. Resulting observations entail the reduction of inference combinations and by extension a computational gain to select the most sensitive pieces of information. © 2017 Computer-Aided Civil and Infrastructure Engineering

Path planning of an autonomous vehicle as a non-holonomic system is an essential part for many automated driving applications. Parking a car into a parking lot and maneuvering it through a narrow corridor would be a common driving scenarios in an urban environment. In this study a hybrid approach for dynamic path planning is presented which deals with the limited degrees of freedom of a non-holonomic system, as well as the real-time constraints and limited computational power. Furthermore, it takes into account ride comfort of the passenger by generating smooth path. The proposed method has been evaluated in simulation environment and is implemented and tested on a Toyota Prius test vehicle with an active steering system.

Façade elements are themost vulnerable parts of buildings with respect to wind loading. In this paper it is assessed to what extent wind-loaded façade elements fulfill the minimum reliability requirements as set in the Eurocodes. The reliability analysis needed for this assessment should account for the uncertainties in each of the parameters relevant for design; both in the structural resistance part and in the wind-loading part. Additionally, the analysis needs to account for the uncertainties in the physical models as such. Until now, no generally applicable assessment procedure exists for this purpose. By combining the knowledge of existing literature, this paper provides a generally applicable assessment procedure that is able to determine the structural reliability of wind loaded façade elements in terms of the failure probability. The assessment procedure uses in-situ wind speed measurements obtained from meteorological stations and location-specific pressure coefficient measurements obtained from boundary-layer wind-tunnels. Wind-directionality effects are taken into account explicitly. In order to show its potential, the assessment procedure is applied on a case-study. The results show that, due to wind-directionality effects, the failure probability of the façade elements is highly dependent on the orientation of the building. Furthermore the results show that the failure probability is almost fully determined by the governing incident wind-directions only.

In many cultures in the past, sustainability used to be an integral concept, related to building traditions, crafts and daily life.With the increasing complexity of our society and the progressive shift from the local to the global scale the past sustainable building tradition has often faded out, without being substituted by a new, equally effective one. Often in the past tradition, real nature-based and climate adapted construction methods have been used. An example is described and observations are made of an ensemble of vernacular architecture and its intrinsic sustainable approach. Part of the buildings concerned is nowadays qualified as UNESCO world heritage. The way conservation of the heritage has been approached in this situation during the 20th century is exemplary for the (mis)belief that technology can solve everything.A new direction for technical conservation was finally chosen, showing that a combination of vernacular approach and modern technology can offer new perspectives for sustainable conservation.

Het Domplein in Utrecht bevindt zich op de plaats van het Romeinse castellum Traiectum (Fig. 1), onderdeel van de verdedigingslinie langs de noordgrens van het Romeinse rijk, de zogenaamde limes. Het Domplein heeft een complexe geschiedenis. Binnen de muren van het castellum zijn verschillende kerken gebouwd en weer gesloopt. De huidige Gothische Dom is de enige overlever. In tegenstelling tot veel andere landen is er in Nederland vrij weinig aandacht besteed aan de bouwmaterialen die de Romeinen hier gebruikten. De aandacht is beperkt tot de verschillende soorten natuursteen die de Romeinen gebruikten. Aan mortels is alleen oppervlakkig aandacht besteed. Deze bijdrage is de eerste studie naar Romeinse mortels van het castellum en één van de belangrijkste vroeg Middeleeuwse bouwwerken daarin, het Bisschoppelijk paleis uit de 11e eeuw. Hoewel bekend was dat dit binnen de perimeter van het oude castellum gelegen moet hebben, is het pas in 2008 herontdekt (Kloosterman 2010).

Chloride induced reinforcement corrosion is the predominant degradation mechanism

design driver for Offshore Wind Turbine (OWT) substructures and also has an im-pact on operational costs. During service life, inspections are required to detect fa-tigue cracks at an early stage. These cracks may need to be repaired. The costs of in-spections and repair are high for offshore structures. To reduce the cost of energy, it is worthwhile to review options to remove unnecessary conservatism in inspections and service life predictions. This paper presents three tools (models) that are un-der development in projects at TNO which aim to reduce the conservatism in fatigue estimations. These tools are respectively: (I) including load cycle history effects in the fatigue crack growth model; (II) a frac-ture toughness model that provides a bet-ter assessment of the maximum allowable crack; and (III) a probabilistic approach to determine inspection intervals based on information gathered during service life.

handrail. This paper demonstrates that aluminium alloys are in principle also suited for heavy loaded structures, such as decks of traffic bridges and helicopter landing platforms. Recent developments in fatigue research is discussed and future research, required for full application of aluminium in heavy loaded structures is identified. The paper ends with a number of examples of heavily loaded infrastructures composed of aluminum alloys.

Offshore Wind power is considered one of the fastest growing maritime sectors and the most promising sources of ‘clean’ energy towards meeting the European targets for 2020 and 2050. The growth of the sector has also been mirrored in other continents like China and US. The technology keeps rapidly growing and the top offshore turbine makers in the industry, Siemens and MHI Vestas, are already developing wind turbines with power ratings up to 7.0 MW and 8.0 MW, respectively. The combination of increasing wind tower heights, rotor blade diameters and water depths, needed for the multi-megawatt wind turbines, makes the need for complex jacket support structures inevitable. As the design of jacket support structures is fatigue driven, the challenge is to balance fatigue performance, structural weight and the operating and maintenance (O&M) strategies in order to reduce the Capital Expenditure (CAPEX) and the Operating Expenditure (OPEX). The current industry-wide accepted methods of fatigue life prediction, according to offshore wind design standards and guidelines, have certain known conservatism. This is due to the uncertainty in load and resistance variables, required safety and assumptions and simplifications in the calculation procedures.

design driver for Offshore Wind Turbine (OWT) substructures and also has an im-pact on operational costs. During service life, inspections are required to detect fa-tigue cracks at an early stage. These cracks may need to be repaired. The costs of in-spections and repair are high for offshore structures. To reduce the cost of energy, it is worthwhile to review options to remove unnecessary conservatism in inspections and service life predictions. This paper presents three tools (models) that are un-der development in projects at TNO which aim to reduce the conservatism in fatigue estimations. These tools are respectively: (I) including load cycle history effects in the fatigue crack growth model; (II) a frac-ture toughness model that provides a bet-ter assessment of the maximum allowable crack; and (III) a probabilistic approach to determine inspection intervals based on information gathered during service life.

Microscopsch (petrografisch) onderzoek van mortels dient een tweeledig doel: het vaststellen van de aard van aantasting van een mortel, of het bepalen van de samenstelling daarvan. Voor dat laatste is het een alternatieve bron naast historische (besteks)gegevens. De microscopisch verkregen informatie is een belangrijk uitgangspunt voor de keuze van restauratiiemortels.

In this paper, a novel distributed consensus control approach for vehicular platooning systems is proposed. In formalizing the underlying consensus problem, a realistic vehicle dynamics model is considered and a velocity-dependent spacing-policy between two consecutive vehicles is realized. For a generic communication topology, conditions for asymptotic platoon stability are proposed. As a particular case, these results allow to consider bi-directional vehicle interaction, which improves the coherence between the vehicles in the platoon. The theoretical results are experimentally validated using a three-vehicle platoon consisting of (longitudinally) automated vehicles equipped with wireless inter-vehicle communication and radar-based sensing.

De gebouwschil wordt steeds meer gebruikt voor de opwekking van energie. Dit is dan ook een gebied waar veel innovaties mogelijk zijn. Diverse partijen zijn hier druk mee bezig. In het kader van de Dutch Green Building Week toonde TNO op 28 september 2016 tijdens het minisym-posium 'Energie producerende gebouwde omgeving' de laatste ontwikkelingen

This paper presents the results of the assessment phase of the project PRIMA (Pro-Active Incident Management), where the benefits, costs and risks of novel traffic incident management techniques are investigated. The project targets the enhancement of current state-of-the-art measures for handling incidents, i.e. road accidents, breakdowns and congestion, by recommending proactive techniques. To this end, modern technologies such as eCall, C2X or xFCD are assessed in terms of their potential to optimize the overall incident duration and response. Results are derived from a scenario-based assessment methodology involving macroscopic traffic simulations, traffic performance calculations and cost-benefit analysis. The work presented in this paper is being followed up by the development of practical guidelines and recommendations for traffic managers of motorways and primary roads.

Occasionally, a profound but distant connection between volcano and culture exists. This is the case between the volcanic Eifel region in Germany and historic construction in the Netherlands, with the river Rhine as physical and enabling connection. Volcanic tuff from the Eifel comprises a significant amount of the building mass in Dutch built heritage. Tuffs from the Laacher See volcano have been imported and used during Roman occupation (hence called Römer tuff). It was the dominant dimension stone when construction in stone revived from the 10th century onwards, becoming the visual mark of Romanesque architecture in the Netherlands. Römer tuff gradually disappeared from the market from the 12th century onwards. Early 15th century, Weiberner tuff from the Riedener caldera, was introduced for fine sculptures and cladding; it disappears from use in about a century. Late 19th century, this tuff is reintroduced, both for restoration and for new buildings. In this period, Ettringer tuff, also from the Riedener caldera, is introduced for the first time. Ground Römer tuff (Rhenish trass) was used as a pozzolanic addition to lime mortars, enabling the hydraulic engineering works in masonry that facilitated life and economics in the Dutch delta for centuries.

In this paper, a novel distributed consensus control approach for vehicular platooning systems is proposed. In formalizing the underlying consensus problem, a realistic vehicle dynamics model is considered and a velocity-dependent spacing-policy between two consecutive vehicles is realized. For a generic communication topology, conditions for asymptotic platoon stability are proposed. As a particular case, these results allow to consider bi-directional vehicle interaction, which improves the coherence between the vehicles in the platoon. The theoretical results are experimentally validated using a three-vehicle platoon consisting of (longitudinally) automated vehicles equipped with wireless inter-vehicle communication and radar-based sensing.

This paper considers local buckling of perforated square aluminium plates. Plates of various slenderness with simply supported edges and subjected to uniaxial compression are studied using the finite element method. Different perforation patterns are investigated, from a single circular hole to 25 circular holes distributed over the plate. A number of aluminium alloys are considered and compared to steel grade A36. Results show that the resistance of the plates containing a single central cut-out is higher than that of plates with more holes and of equal total cut-out size. A further refinement beyond 5 holes does not influence the resistance

In order to satisfy the need for good quality UNDerwater EXplosion (UNDEX) response estimates of naval platforms, TNO developed two 3D simulation tools: the Simplified Interaction Tool (SIT) and the hydro/structural code 3DCAV. Both tools are an add-on to LS-DYNA. SIT is a module of user routines for generating the UNDEX loading and accounts for the strong fluid-structure interaction on the wet hull of a 3D finite element model of the platform structure by means of sophisticated physical approximation. This eliminates the need for a 3D modelling of the surrounding water, such as necessary for advanced coupled finite element/hydrocode simulations. Both the shock wave stage with reflections and cavitation and the subsequent gas bubble loading are modelled in SIT. The SIT was tuned and validated using experimental data from full-scale surface ship shock trials. 3DCAV is a module of user routines that uses LS-DYNA’s Lagrangian fluid elements as a hydrocode for performing UNDEX simulations with less physical approximations. The results from 3DCAV simulations are used for tuning and validating the more efficient SIT for new applications like submarines and non-standard UNDEX scenarios for surface ships. A typical simulation of a detailed 3D finite element model of a naval platform takes only hours for a SIT simulation of the shock wave stage against days for a comparable 3DCAV simulation. Nevertheless, 3DCAV is still much more efficient compared to coupled Eulerian-Lagrangian hydrocodes. Its simulation efficiency has made SIT a prime UNDEX simulation tool for use in platform design, while 3DCAV remains highly useful for verification, validation and further SIT development. This paper provides a short overview of the physical backgrounds of SIT and 3DCAV, a comparison of their performance and examples of applications.

This paper presents a battery peak power shaving strategy for battery electric buses. The developed strategy restricts the battery charge/discharge power when the propulsion power demand is high to avoid high deterioration of the battery capacity during operation. Without reducing the propulsion power, the developed strategy optimizes the power demand of the passenger cabin air conditioning system while guaranteeing the passenger temperature comfort. An equivalent consumption minimization strategy (ECMS) technique is extended to include the thermal comfort of the passenger in the energy management system of the bus. The developed strategy is analytical, real-time implementable and verified via hardware-in-the-loop test. Simulation results demonstrate the capability for satisfying the propulsion power demand and passenger temperature comfort while reducing the battery peak power (up to 20% during acceleration) to restrict the battery degradation significantly.

Where exposed to an aggressive environment, concrete structures will develop reinforcement corrosion at some point in their life. Chloride ions from de-icing salt or sea water induce pitting corrosion. Local cross section reduction may occur relatively quickly and expansion due to corrosion products precipitating may crack and spall concrete cover and reduce steel-concrete bond. With the aging of the existing stock, questions arise about the effects of corrosion on their structural behaviour, safety and reliability.TNOhas started a four-year programme to investigate this subject. One project concerns modelling of pitting corrosion from electrochemical principles, aimed at prediction of cross section loss with time and, in a next stage, corrosion product formation. Existing models for pitting corrosion are highly simplified and essentially two-dimensional, while pitting is clearly a three-dimensional phenomenon. The difference may have serious consequences for structural safety. New approaches are needed, including new conceptual models and addressing uncertainties on several levels. The paper presents some conceptual models for pitting corrosion and reports preliminary results of numerical (finite element) modelling of pitting corrosion, based on solving potential and current distributions and resulting in cross section loss as a function of time. Further work including experimental validation is foreseen.

De gebouwschil wordt steeds meer gebruikt voor de opwekking van energie. Dit is dan ook een gebied waar veel innovaties mogelijk zijn. Diverse partijen zijn hier druk mee bezig. In het kader van de Dutch Green Building Week toonde TNO op 28 september 2016 tijdens het minisym-posium 'Energie producerende gebouwde omgeving' de laatste ontwikkelingen

Occasionally, a profound but distant connection between volcano and culture exists. This is

Vanaf de Romeinse tijd tot in de 19e eeuw is historisch metselwerk in monumenten en ander gebouwd erfgoed vaak vervaardigd met kalk- of kalk-puzzolaanmortels. Sommige kalken zijn van nature in meer of mindere mate hydraulisch. In de 19e eeuw begint wetenschappelijk onderzoek naar hydraulisch bindmiddelen en doen natuurlijke hydraulisch kalk, Portland cement en voorlopers daarvan hun intrede. Deze bijdrage geeft een beknopt overzicht van historische mortels, met bijzondere aandacht aan hun gebruik in Nederland

Het Domplein in Utrecht bevindt zich op de plaats van het Romeinse castellum Traiectum (Fig. 1), onderdeel van de verdedigingslinie langs de noordgrens van het Romeinse rijk, de zogenaamde limes. Het Domplein heeft een complexe geschiedenis. Binnen de muren van het castellum zijn verschillende kerken gebouwd en weer gesloopt. De huidige Gothische Dom is de enige overlever. In tegenstelling tot veel andere landen is er in Nederland vrij weinig aandacht besteed aan de bouwmaterialen die de Romeinen hier gebruikten. De aandacht is beperkt tot de verschillende soorten natuursteen die de Romeinen gebruikten. Aan mortels is alleen oppervlakkig aandacht besteed. Deze bijdrage is de eerste studie naar Romeinse mortels van het castellum en één van de belangrijkste vroeg Middeleeuwse bouwwerken daarin, het Bisschoppelijk paleis uit de 11e eeuw. Hoewel bekend was dat dit binnen de perimeter van het oude castellum gelegen moet hebben, is het pas in 2008 herontdekt (Kloosterman 2010).

Microscopsch (petrografisch) onderzoek van mortels dient een tweeledig doel: het vaststellen van de aard van aantasting van een mortel, of het bepalen van de samenstelling daarvan. Voor dat laatste is het een alternatieve bron naast historische (besteks)gegevens. De microscopisch verkregen informatie is een belangrijk uitgangspunt voor de keuze van restauratiiemortels.

This paper presents the results of the assessment phase of the project PRIMA (Pro-Active Incident Management), where the benefits, costs and risks of novel traffic incident management techniques are investigated. The project targets the enhancement of current state-of-the-art measures for handling incidents, i.e. road accidents, breakdowns and congestion, by recommending proactive techniques. To this end, modern technologies such as eCall, C2X or xFCD are assessed in terms of their potential to optimize the overall incident duration and response. Results are derived from a scenario-based assessment methodology involving macroscopic traffic simulations, traffic performance calculations and cost-benefit analysis. The work presented in this paper is being followed up by the development of practical guidelines and recommendations for traffic managers of motorways and primary roads.

Clause 6.2.8 of EN 1993-1-1 covers the design rules on bending-shear resistance, taking presence of shear into account by a reduced yield stress for the shear area. Numerical research on bending-shear interaction by means of the Abaqus Finite Element modelling soft-ware is presented. The numerical model is validated against the experimental results. A material model based on various tensile test coupons was used incorporating the actual material proper-ties within the tested cross-section. Strong axis three-point bending tests were simulated by means of continuum solid elements. Good agreement was achieved between numerical and experimental result, both are compared with the EN 1993-1-1 design rule.

In order to satisfy the need for good quality UNDerwater EXplosion (UNDEX) response estimates of naval platforms, TNO developed two 3D simulation tools: the Simplified Interaction Tool (SIT) and the hydro/structural code 3DCAV. Both tools are an add-on to LS-DYNA. SIT is a module of user routines for generating the UNDEX loading and accounts for the strong fluid-structure interaction on the wet hull of a 3D finite element model of the platform structure by means of sophisticated physical approximation. This eliminates the need for a 3D modelling of the surrounding water, such as necessary for advanced coupled finite element/hydrocode simulations. Both the shock wave stage with reflections and cavitation and the subsequent gas bubble loading are modelled in SIT. The SIT was tuned and validated using experimental data from full-scale surface ship shock trials. 3DCAV is a module of user routines that uses LS-DYNA’s Lagrangian fluid elements as a hydrocode for performing UNDEX simulations with less physical approximations. The results from 3DCAV simulations are used for tuning and validating the more efficient SIT for new applications like submarines and non-standard UNDEX scenarios for surface ships. A typical simulation of a detailed 3D finite element model of a naval platform takes only hours for a SIT simulation of the shock wave stage against days for a comparable 3DCAV simulation. Nevertheless, 3DCAV is still much more efficient compared to coupled Eulerian-Lagrangian hydrocodes. Its simulation efficiency has made SIT a prime UNDEX simulation tool for use in platform design, while 3DCAV remains highly useful for verification, validation and further SIT development. This paper provides a short overview of the physical backgrounds of SIT and 3DCAV, a comparison of their performance and examples of applications.

Clause 6.2.8 of EN 1993-1-1 covers the design rules on bending-shear resistance, taking presence of shear into account by a reduced yield stress for the shear area. Numerical research on bending-shear interaction by means of the Abaqus Finite Element modelling soft-ware is presented. The numerical model is validated against the experimental results. A material model based on various tensile test coupons was used incorporating the actual material proper-ties within the tested cross-section. Strong axis three-point bending tests were simulated by means of continuum solid elements. Good agreement was achieved between numerical and experimental result, both are compared with the EN 1993-1-1 design rule.

Many aluminium structures contain welded and bolted connections that are modeled as one or more equivalent T-stubs – also referred to as tension zone components – for the structural assessment. Knowledge on the structural behavior of such T-stubs is thus essential for proper designs. However, this behavior has never been checked for fire conditions. In this paper, the structural behavior of aluminium T-stubs exposed to fire is studied through a combination of tests, finite element simulations, and theoretical models. A safe and conservative assessment procedure is developed for determining the critical temperature, based on the material deterioration as a function of temperature. This enables engineers and practitioners to determine a conservative value of the fire resistance.

Vanaf de Romeinse tijd tot in de 19e eeuw is historisch metselwerk in monumenten en ander gebouwd erfgoed vaak vervaardigd met kalk- of kalk-puzzolaanmortels. Sommige kalken zijn van nature in meer of mindere mate hydraulisch. In de 19e eeuw begint wetenschappelijk onderzoek naar hydraulisch bindmiddelen en doen natuurlijke hydraulisch kalk, Portland cement en voorlopers daarvan hun intrede. Deze bijdrage geeft een beknopt overzicht van historische mortels, met bijzondere aandacht aan hun gebruik in Nederland

In many cultures in the past, sustainability used to be an integral concept, related to building traditions, crafts and daily life.With the increasing complexity of our society and the progressive shift from the local to the global scale the past sustainable building tradition has often faded out, without being substituted by a new, equally effective one. Often in the past tradition, real nature-based and climate adapted construction methods have been used. An example is described and observations are made of an ensemble of vernacular architecture and its intrinsic sustainable approach. Part of the buildings concerned is nowadays qualified as UNESCO world heritage. The way conservation of the heritage has been approached in this situation during the 20th century is exemplary for the (mis)belief that technology can solve everything.A new direction for technical conservation was finally chosen, showing that a combination of vernacular approach and modern technology can offer new perspectives for sustainable conservation.

This paper presents a risk-based method to quantify climate change effects on road infrastructure, as a support for decision-making on interventions. This can be implemented in climate adaptation plans as an element of asset management. The method is illustrated by a specific case in which traffic on a road network is disrupted by the flooding of a tunnel due to extreme rainfall. Novel techniques to describe both probability of occurrence and consequences of an event are integrated into the proposed risk-based approach. To model a typical climate-change related phenomenon, i.e. rainfall intensity-duration, a model using copulas is proposed as well as a method to account for uncertainty using structured expert judgement. To quantify the consequences, an existing quick scan tool is adopted. The method calculates the risk of flooding of a tunnel, expressed in both probability of occurrence and subsequent additional travel duration on the road network. By comparison of this evolving risk to a societally acceptable threshold, the remaining resilience of the tunnel is evaluated. Furthermore, the method assesses the development of the resilience over time as a result of projected climate change. The maximum time-to-intervention is defined as the period up until the moment when the resilience is depleted. By application of the method to a tunnel in two different contexts, i.e. in a regional road network and a highway network, it is shown that the consequences of tunnel flooding may differ by an order of magnitude (25-fold for the example). Using a risk-based decision-making perspective leads to significant differences in the maximum time-to-intervention. In the example case the year of intervention is determined at 2020 for a tunnel in a highway network, while interventions can be postponed until 2140 in a regional road network. © 2016, Editorial Board EJTIR. All rights reserved.

Façade elements are themost vulnerable parts of buildings with respect to wind loading. In this paper it is assessed to what extent wind-loaded façade elements fulfill the minimum reliability requirements as set in the Eurocodes. The reliability analysis needed for this assessment should account for the uncertainties in each of the parameters relevant for design; both in the structural resistance part and in the wind-loading part. Additionally, the analysis needs to account for the uncertainties in the physical models as such. Until now, no generally applicable assessment procedure exists for this purpose. By combining the knowledge of existing literature, this paper provides a generally applicable assessment procedure that is able to determine the structural reliability of wind loaded façade elements in terms of the failure probability. The assessment procedure uses in-situ wind speed measurements obtained from meteorological stations and location-specific pressure coefficient measurements obtained from boundary-layer wind-tunnels. Wind-directionality effects are taken into account explicitly. In order to show its potential, the assessment procedure is applied on a case-study. The results show that, due to wind-directionality effects, the failure probability of the façade elements is highly dependent on the orientation of the building. Furthermore the results show that the failure probability is almost fully determined by the governing incident wind-directions only.

Offshore Wind power is considered one of the fastest growing maritime sectors and the most promising sources of ‘clean’ energy towards meeting the European targets for 2020 and 2050. The growth of the sector has also been mirrored in other continents like China and US. The technology keeps rapidly growing and the top offshore turbine makers in the industry, Siemens and MHI Vestas, are already developing wind turbines with power ratings up to 7.0 MW and 8.0 MW, respectively. The combination of increasing wind tower heights, rotor blade diameters and water depths, needed for the multi-megawatt wind turbines, makes the need for complex jacket support structures inevitable. As the design of jacket support structures is fatigue driven, the challenge is to balance fatigue performance, structural weight and the operating and maintenance (O&M) strategies in order to reduce the Capital Expenditure (CAPEX) and the Operating Expenditure (OPEX). The current industry-wide accepted methods of fatigue life prediction, according to offshore wind design standards and guidelines, have certain known conservatism. This is due to the uncertainty in load and resistance variables, required safety and assumptions and simplifications in the calculation procedures.

In the offshore industry, fibre reinforced sliding journal bearings are increasingly used due to their low-maintenance and self-lubricating characteristics. To be able to use the bearings in the rough offshore environment, under heavy loading, full scale tests are essential to assess the friction and wear rate development during use. For this purpose, two full scale wear tests were performed on composite sliding journal bearings of 300 mm in diameter. These tests were performed at the laboratory of TNO Structural Dynamics in Delft, The Netherlands, over a period of eight months. For this purpose, a test rig was designed in which a shaft runs through the journal bearing. The latter is loaded in the range 50 to 700 kN and the shaft is given triangle-like cyclic displacements. To be able to test under realistic conditions, the bearing is constantly submerged in flowing seawater. Forces, displacements and temperatures were constantly monitored to manage the system and determine the parameters. Besides a description of the test rig, a rationale of choices made, observations during testing and detailed cycle-by-cycle friction characteristics are presented, next to generalized trends for the wear and Coefficients of Friction (CoFs) under the various loading conditions.

In verschillende perioden zijn diverse tufstenen uit de Eifel in Nederland ingevoerd om te dienen als bouwmateriaal: de zogenaamde Römer tuf, in de Romeinse tijd en in de periode van Romaanse architectuur in de Middeleeuwen, Weiberner tuf, in de late Middeleeuwen en opnieuw vanaf halverwege de 19e eeuw en Ettringer tuf, eveneens vanaf halverwege de 19e eeuw. Tezamen vormen ze een niet onaanzienlijk deel van de bouwmassa in Nederlandse monumenten: Een succesverhaal voor een steen die erg poreus en niet al te sterk is

In het kader van de samenwerking MonumentenKennis is niet alleen nieuw onderzoek gedaan, maar ook aandacht besteed aan kennisoverdracht op het gebied van natuursteen. Het betreft: • Het opstellen van een handleiding voor het herkennen van natuursteen gebruikt in Nederlands gebouwd erfgoed tot ca. 1840. • Het maken van een handleiding voor het herkennen van afwerkingen op natuursteen. • Het ontsluiten van de natuursteencollecties van de TU Delft en de RCE. • Het maken van een database van het gebruik van natuursteensoorten aan monumenten in Nederland. • Het herzien van de natuursteen schade-atlas in het Monument Diagnose en Conservering Systeem. Al deze producten zullen in de loop van 2016 beschikbaar komen via de website van MonumentenKennis

The question ‘What is the importance of a Monumentenwacht system (monument watch)’ is a very current issue. Do the activities of Monumentenwacht (often abbreviated MW in this report) contribute to better and more cost-effective preservation of our built cultural heritage? In order to answer this question, research has been conducted whereby the focus lay on identifying the consequences for monument preservation of the failure and damage mechanisms that can influence the state of conservation of a monument. Then, the activities of MW were examined in terms of their influence on these consequences. Might the processes have a lesser impact thanks to MW? Besides an analysis of the so-called failure mechanisms, direct consideration was given to the manner of operation of a team of inspectors, and interviews were conducted with representatives of several relevant parties in this field: an owner of a historical monument, an architect, a representative of a quality assurance foundation, a representative of the government, a restoration contractor and an insurance company. The research into the importance of MW is carried out by TNO and TU Delft at the assignment of Monumentenwacht Noord-Brabant (MW North-Brabant). This research does not strive to express the importance of Monumentenwacht in exact financial numbers. This would entail looking at the cost of MW consultation, followed by maintenance or intervention based on the advice on the one hand, compared to different degrees of intervention, varying from doing nothing to complete restoration on the other.

‘Groen bouwen’ is typisch een kreet van deze tijd. Toch werd in het verleden, met name rond Soest in Westfalen (Duitsland) ook al groen gebouwd. Over de huidige betekenis van milieuvriendelijk maakte men zich wellicht niet druk, maar er werd een opmerkelijke groene natuursteen gebruikt; de steen is ook in Nederland toegepast. In deze bijdrage een kort overzicht van het ontstaan en het gebruik van Anröchter Grünstein.

Vanuit Nederlands perspectief kan het Zevengebergte aan de Rijn tegenover Bonn als één grote groeve worden beschouwd. In de middeleeuwen leverde het gebied de bekende Drachenfels trachiet. In de 19e eeuw stichten Nederlanders de Basalt AG in Linz om aan de grote vraag naar basalt voor waterbouwkundige werken te kunnen voldoen. Zelfs de natuursteen afkomstig van de sloop van de lokale abdij van Heisterbach werd gebruikt voor de aanleg van het kanaal Venlo-Neuss. Recent is gebleken dat de Romeinen ook al basalt uit het Zevengebergte naar Nederland importeerden

Natuursteen maakt een niet onaanzienlijk deel uit van de bouwmassa aan monumenten in Nederland. In een land als Nederland waar ‘harde’ steen, in tegenstelling tot zand, klei en grind, dun gezaaid is, bieden gevels bij uitstek een gelegenheid steensoorten en geologische fenomenen van nabij te bekijken. We vertellen u niets nieuws. Al in de jaren ‘80 van de vorige eeuw verschenen de boekjes Steenrijk Amsterdam van Wim Dubelaar (1984) en Steengoed Groningen van Harry Huisman (1987). De afgelopen jaren verscheen een reeks boeken over natuursteen in monumenten in Nederland en Vlaanderen van verschillende auteurs, waaronder Natuursteen in Limburgse monumenten (2001), Utrecht in steen (2007), Gent... steengoed ! (2009), Natuursteen in Vlaanderen, versteend verleden (2009), Onvermoede weelde (2012) Belgisch marmer (2014) en eerder dit jaar Aachener Natursteine (2015). In 2006 gaf de Nederlandse Geologische Vereniging De geologische stad - steeds natuursteen uit, met centraal daarin wandelingen langs natuursteen in twaalf steden. Heel veel informatie, deels in handzame gidsen, deels in boeken voor thuis

The AutoR-project takes a holistic approach to reduce the cost of heliostat fields: Wireless control and energy supply enables to use smaller heliostats which need less steel per mirror area (but usually have high wiring cost). A low cost but high efficient drive system is chosen which reduces energy consumption to a minimum amount and leads to low cost for PV cell and energy storage. The usual boundary layer wind tunnels tests for heliostats are proven regarding energy spectra to avoid oversizing of steel structure and drives or failures because of underestimations of the loads. The concepts for wireless control and energy supply, the wind tunnel investigations and the first rim drive heliostat prototype are presented. © 2015 The Authors. Published by Elsevier Ltd.