Search results

Simulations exist for the prediction of the behaviour of building structural systems under fire, including two-way coupled fire-structure interaction. However, these simulations do not include detailed models of the connections, whereas these connections may impact the overall behaviour of the structure. Therefore, this paper proposes a two-scale method to include screw connections.

The two-scale method consists of (a) a global-scale model that models the overall structural system and (b) a small-scale model to describe a screw connection. Components in the global-scale model are connected by a spring element instead of a modelled screw, and the stiffness of this spring element is predicted by the small-scale model, updated at each load step. For computational efficiency, the small-scale model uses a proprietary technique to model the behaviour of the threads, verified by simulations that model the complete thread geometry, and validated by existing pull-out experiments. For four screw failure modes, load-deformation behaviour and failure predictions of the two-scale method are verified by a detailed system model. Additionally, the two-scale method is validated for a combined load case by existing experiments, and demonstrated for different temperatures. Finally, the two-scale method is illustrated as part of a two-way coupled fire-structure simulation.

It was shown that proprietary ”threaded connection interaction” can predict thread relevant failure modes, i.e. thread failure, shank tension failure, and pull-out. For bearing, shear, tension, and pull-out failure, load-deformation behaviour and failure predictions of the two-scale method correspond with the detailed system model and Eurocode predictions. Related to combined load cases, for a variety of experiments a good correlation has been found between experimental and simulation results, however, pull-out simulations were shown to be inconsistent.

More research is needed before the two-scale method can be used under all conditions. This relates to the failure criteria for pull-out, combined load cases, and temperature loads.

The two-scale method bridges the existing very detailed small-scale screw models with present global-scale structural models, that in the best case only use springs. It shows to be insightful, for it contains a functional separation of scales, revealing their relationships, and it is computationally efficient as it allows for distributed computing. Furthermore, local small-scale non-convergence (e.g. a screw failing) can be handled without convergence problems in the global-scale structural model.

This paper aims to review recent literature results on the mechanical response of confined pentamode structures behaving either in the stretching-dominated or the bending-dominated regimes.

The analyzed structures consist of multilayer systems formed by pentamode lattices alternated with stiffening plates and are equipped with rigid or hinged connections.

It is shown that such structures are able to carry unidirectional compressive loads with sufficiently high stiffness, while showing markedly low stiffness against shear loads. In particular, their shear stiffness may approach zero in the stretching-dominated regime.

The presented results highlight the high engineering potential of laminated pentamode metamaterials as novel isolation devices to be used for the protection of buildings against shear waves.

Attempts to transform health systems have in many countries involved starting to pay healthcare providers through a DRG system, but that has involved managerial workarounds. Managerial workarounds have seldom been analysed. This paper does so by extending and modifying existing knowledge of the causes and character of clinical and IT workarounds, to produce a conceptualisation of the managerial workaround. It further develops and revises this conceptualisation by comparing the practical management, at both provider and purchaser levels, of hospital DRG payment systems in England, Germany and Italy.

We make a qualitative test of our initial assumptions about the antecedents, character and consequences of managerial workarounds by comparing them with a systematic comparison of case studies of the DRG hospital payment systems in England, Germany and Italy. The data collection through key informant interviews (N = 154), analysis of policy documents (N = 111) and an action learning set, began in 2010–12, with additional data collection from key informants and administrative documents continuing in 2018–19 to supplement and update our findings.

Managers in all three countries developed very similar workarounds to contain healthcare costs to payers. To weaken DRG incentives to increase hospital activity, managers agreed to lower DRG payments for episodes of care above an agreed case-load ‘ceiling' and reduced payments by less than the full DRG amounts when activity fell below an agreed ‘floor' volume.

Empirically this study is limited to three OECD health systems, but since our findings come from both Bismarckian (social-insurance) and Beveridge (tax-financed) systems, they are likely to be more widely applicable. In many countries, DRGs coexist with non-DRG or pre-DRG systems, so these findings may also reflect a specific, perhaps transient, stage in DRG-system development. Probably there are also other kinds of managerial workaround, yet to be researched. Doing so would doubtlessly refine and nuance the conceptualisation of the ‘managerial workaround’ still further.

In the case of DRGs, the managerial workarounds were instances of ‘constructive deviance' which enabled payers to reduce the adverse financial consequences, for them, arising from DRG incentives. The understanding of apparent failures or part-failures to transform a health system can be made more nuanced, balanced and diagnostic by using the concept of the ‘managerial workaround'.

Managerial workarounds also appear outside the health sector, so the present analysis of managerial workarounds may also have application to understanding attempts to transform such sectors as education, social care and environmental protection.

So far as we are aware, no other study presents and tests the concept of a ‘managerial workaround'. Pervasive, non-trivial managerial workarounds may be symptoms of mismatched policy objectives, or that existing health system structures cannot realise current policy objectives; but the workarounds themselves may also contain solutions to these problems.

The microseismic monitoring technique has great advantages on identifying the location, extent and the mechanism of damage process occurring in rock mass. This study aims to analyze distribution characteristics and the evolution law of excavation damage zone of surrounding rock based on microseismic monitoring data.

In situ test using microseismic monitoring technique is carried out in the large-span transition tunnel of Badaling Great Wall Station of Beijing-Zhangjiakou high-speed railway. An intelligent microseismic monitoring system is built with symmetry monitoring point layout both on the mountain surface and inside the tunnel to achieve three-dimensional and all-round monitoring results.

Microseismic events can be divided into high density area, medium density area and low density area according to the density distribution of microseismic events. The positions where the cumulative distribution frequencies of microseismic events are 60 and 80% are identified as the boundaries between high and medium density areas and between medium and low density areas, respectively. The high density area of microseismic events is regarded as the high excavation damage zone of surrounding rock, which is affected by the grade of surrounding rock and the span of tunnel. The prediction formulas for the depth of high excavation damage zone of surrounding rock at different tunnel positions are given considering these two parameters. The scale of the average moment magnitude parameters of microseismic events is adopted to describe the damage degree of surrounding rock. The strong positive correlation and multistage characteristics between the depth of excavation damage zone and deformation of surrounding rock are revealed. Based on the depth of high excavation damage zone of surrounding rock, the prestressed anchor cable (rod) is designed, and the safety of anchor cable (rod) design parameters is verified by the deformation results of surrounding rock.

The research provides a new method to predict the surrounding rock damage zone of large-span tunnel and also provides a reference basis for design parameters of prestressed anchor cable (rod).

How does the human brain absorb information and turn it into skills of its own in psychotherapy? In an attempt to answer this question, the authors will review the intricacies of processing channels in psychotherapy and propose the term transprocessing (as in transduction and processing combined) for the underlying mechanisms. Through transprocessing the brain processes multimodal memories and creates reparative solutions in the course of psychotherapy. Transprocessing is proposed as a stage-sequenced mechanism of deconstruction of engrained patterns of response. Through psychotherapy, emotional-cognitive reintegration and its consolidation is accomplished. This process is mediated by cellular and neural plasticity changes.

The main objective of the present research is to investigate the benefits of using geogrid reinforcement in minimizing the rate of deterioration of ballasted rail track geometry resting on soft clay and to explore the effect of load amplitude, load frequency, presence of geogrid layer in ballast layer and ballast layer thickness on the behavior of track system. These variables are studied both experimentally and numerically. This paper examines the effect of geogrid reinforced ballast laying on a layer of clayey soil as a subgrade layer, where a half full scale railway tests are conducted as well as a theoretical analysis is performed.

The experimental tests work consists of laboratory model tests to investigate the reduction in the compressibility and stress distribution induced in soft clay under a ballast railway reinforced by geogrid reinforcement subjected to dynamic load. Experimental model based on an approximate half scale for general rail track engineering practice is adopted in this study which is used in Iraqi railways. The investigated parameters are load amplitude, load frequency and presence of geogrid reinforcement layer. A half full-scale railway was constructed for carrying out the tests, which consists of two rails 800 mm in length with three wooden sleepers (900 mm × 90 mm × 90 mm). The ballast was overlying 500 mm thick clay layer. The tests were carried out with and without geogrid reinforcement, the tests were carried out in a well tied steel box of 1.5 m length × 1 m width × 1 m height. A series of laboratory tests were conducted to investigate the response of the ballast and the clay layers where the ballast was reinforced by a geogrid. Settlement in ballast and clay, was measured in reinforced and unreinforced ballast cases. In addition to the laboratory tests, the application of numerical analysis was made by using the finite element program PLAXIS 3D 2013.

It was concluded that the settlement increased with increasing the simulated train load amplitude, there is a sharp increase in settlement up to the cycle 500 and after that, there is a gradual increase to level out between, 2,500 and 4,500 cycles depending on the load frequency. There is a little increase in the induced settlement when the load amplitude increased from 0.5 to 1 ton, but it is higher when the load amplitude increased to 2 ton, the increase in settlement depends on the geogrid existence and the other studied parameters. Both experimental and numerical results showed the same behavior. The effect of load frequency on the settlement ratio is almost constant after 500 cycles. In general, for reinforced cases, the effect of load frequency on the settlement ratio is very small ranging between 0.5 and 2% compared with the unreinforced case.

Increasing the ballast layer thickness from 20 cm to 30 cm leads to decrease the settlement by about 50%. This ascertains the efficiency of ballast in spreading the waves induced by the track.

This paper aims to provide an overview of the current manufacturing methods for three-dimensional textile preforms while providing experimental data on the emerging techniques of combining yarn interlocking with yarn interlooping.

The paper describes the key textile technologies used for composite manufacture: braiding, weaving and knitting. The various textile preforming methods are suited to different applications; their capabilities and end performance characteristics are analysed.

Such preforms are used in composites in a wide range of industries, from aerospace to medical and automotive to civil engineering. The paper highlights how the use of knitting technology for preform manufacture has gained wider acceptance due to its flexibility in design and shaping capabilities. The tensile properties of glass fibre knit structures containing inlay yarns interlocked between knitted loops are given, highlighting the importance of reinforcement yarns.

The future trends of reinforcement yarns in knitted structures for improved tensile properties are discussed, with initial experimental data.

Although an increasing number of PhD holders will continue their careers outside academia, we know little about their further career prospects. To develop a better understanding of how this group constructs and justifies a successful career outside academia, we conducted semi-structured interviews with 47 PhD graduates from different disciplines (humanities, social and beta sciences) who have obtained elaborate experience working outside academia.

Drawing on a multi-career perspective, we explored the motivations of the PhD holders when making such career transitions. The findings from the interviews demonstrated how PhD holders’ main motivations were associated with their perceived organizational, community and cognitive careers. Our data analysis revealed that these motivations related to PhD holders and can be grouped along four key tensions:

• distanced from real life (academia) versus appreciating the practical impact of their research (currently);

• competition and performance orientation (academia) versus enjoying their current multidisciplinary collaboration towards a common goal (current);

• Individualism and loneliness were typically experienced in academia versus autonomy and intellectual stimulation in their current work; and

• lack of stable career perspectives in academia versus current options for competence-based development and personal growth.

distanced from real life (academia) versus appreciating the practical impact of their research (currently);

competition and performance orientation (academia) versus enjoying their current multidisciplinary collaboration towards a common goal (current);

Individualism and loneliness were typically experienced in academia versus autonomy and intellectual stimulation in their current work; and

lack of stable career perspectives in academia versus current options for competence-based development and personal growth.

Thus, while discontinuation of an academic career may easily hold a pejorative connotation, the analysis of the PhD holders’ motivations revealed important and rewarding opportunities in pursuing a career in other sectors. Overall, from our study, we can conclude that while a major gap may exist between careers in academia and ‘the corporate world’, shifting careers between these worlds is not as ‘unthinkable’ as commonly believed.

The “unplannable” is a welcomed exception to the formal order of urban planning. This opinion article explores some examples of informal urbanism and discusses its ambiguous relationship to public space and unplanned activities in the city. The informal sector offers important lessons about the adaptive use of space and its social role. The article examines the ways specific groups appropriate informal spaces and how this can add to a city’s entrepreneurship and success. The characteristics of informal, interstitial spaces within the contemporary city, and the numerous creative ways in which these temporarily used spaces are appropriated, challenge the prevalent critical discourse about our understanding of authorised public space, formal place-making and social order within the city in relation to these informal spaces.

The text discusses various cases from Chile, the US and China that illustrate the dilemma of the relationship between informality and public/private space today. One could say that informality is a deregulated self-help system that redefines relationships with the formal. Temporary or permanent spatial appropriation has behavioural, economic and cultural dimensions, and forms of the informalare not always immediately obvious: they are not mentioned in building codes and can often be subversive or unexpected, emerging in the grey area between legal and illegal activities.

The chapters in this book show that it is possible to conduct studies on the intersections between gender, criminalization, imprisonment, and human rights in Southeast Asia. In this conclusion, we draw out the implications of this emerging scholarship. More specifically, we critically examine how common talk about “individual needs” risks blinding criminal justice reformers to the structural, gendered dynamics that render people criminalizable and imprisonable. We explore the potential of the concept of participation to strengthen understandings and activism around gendered harms, and grapple with the thorny issue of for whom we speak. We advocate for cross-cultural understandings, developed in collaboration and through partnership, to productively challenge the ethnocentrism of criminology and propel truly transformative agendas. Three steps are identified to decenter research and activism: Scholars and activists must acknowledge the risks of attending to need while not attending to the drivers of need; resist the temptation to operate only within the limits defined by the authorities, the state, the academy, or agencies set up to protect; and generate “home grown,” counter-hegemonic solutions that push back against the tendency to universalize, colonize and deny difference.