Japan Architectural Review最新文献

Urban heat during summer has recently become a serious issue. Although urban trees have a cooling effect, this effect must be evaluated quantitatively for effective landscape and streetscape design. However, models capable of predicting hourly changes in typical tree transpiration under summer conditions at the whole-tree scale rather than the individual-leaf or forest scale are lacking. In addition, leaf surface temperatures in the lower canopy, which significantly affect the radiative environment of pedestrians, must be accurately predicted. Nevertheless, the prediction accuracy of heat balance changes on leaf surfaces due to transpiration has not been adequately validated. Such models must also consider plant physiological responses, which vary with the surrounding physical environment, to ensure high accuracy. In this study, a literature review was performed to identify transpiration and stomatal conductance models that can predict typical transpiration and heat balance properties. Subsequently, hourly transpiration rate changes of the whole tree and spatial distribution of leaf surface temperatures in the lower canopy were measured. The parameters of the stomatal conductance model were also estimated to enable predictions using both models combined. The present model is novel because it reproduces whole-tree transpiration rate characteristics and leaf surface temperature trends in the lower canopy.

This paper proposes a control method for a semi-active controlled tuned mass damper (TMD) adaptable to the period fluctuation of the target structure. It is based on the idea of maximizing the TMD's absorbing energy. First, previous control methods are reviewed from the aspects of performance and applicability. Next, the concept and algorithm of the proposed control method are described, and the relationship between its response control performance and absorbing energy is investigated. Finally, earthquake response analyses are performed that compare the proposed control method with other types of TMD.

Q–Δ resonance is the phenomenon in which the large displacement of a vertical member or structure with different stiffnesses in the two horizontal directions induces a torsional mode response owing to geometric nonlinearity and the related internal resonance. This phenomenon may have a substantial impact on super-high-rise buildings, whose horizontal displacement response can be remarkably large due to long-period ground motion. In this study, the responses of two non-eccentric super-high-rise buildings, which satisfied the Q–Δ resonance conditions, to long-period design ground motions were investigated using 3D frame models. One was a 320-m-tall, center-core, super-high-rise building model with outriggers, and the other was a 200-m-tall, center-core, super-high-rise building model without outriggers, in which the bending deformation became relatively large. Time-history response analysis was conducted considering geometric nonlinearity, and the results suggested that the torsional response induced by the Q–Δ resonance could significantly increase the horizontal acceleration response. The countermeasures against long-period ground motion in super-high-rise buildings should consider the torsional response even in non-eccentric buildings.

The purpose of this study is to clarify which cities in Bavaria are affected by photovoltaic (PV) installation on their urban areas and farmland landscapes and to show the possibility of further expansion in the future. The following two points are obvious. First, rural areas between Munich and Nuremberg and rural areas at the entrance to Bavaria have a high PV installation rate and a high amount of PV electricity per capita. Second, there will be a change in the amount of PV electricity in 2023, with an increase in PV installations biased toward either buildings or farmland.

Lessons learned from earthquake damage in recent years revealed that damage to reinforced concrete (RC) structural members was limited; however, nonstructural members were significantly damaged, making continuous building occupancy difficult. In this study, a laboratory test was conducted to elucidate the effects of nonstructural flat walls on the seismic behavior/performance of a model frame representing the lower 2.5 stories of high-rise RC buildings. It was found that the nonstructural flat walls contributed to increasing the shear strength of the frame; however, the shear forces applied to the structural members of the columns and beams also increased.

As a country that implements sustainable development, Indonesia sets goals for energy efficiency, especially in the building sector. School buildings as representative building stock are the target of this study. The surveys and data collection were done from 28 high schools in Makassar. In the early stage of energy efficiency design, it is important to investigate the actual condition of school buildings as a foundation for further studies in energy consumption and energy efficiency planning. This paper comprehensively analyzes a typical school building, energy consumption patterns, and constant usage. Besides that, the effect of building conditions on school energy consumption is discussed. The findings of this study indicate that typical school buildings are usually in the south direction where site plan adjacent to the buildings around could lead to some challenges in energy efficiency. The energy consumption pattern reveals two categories, Category 1 has high fluctuation for monthly energy consumption and Category 2 has relatively flat consumption. Thus, two categories may have different site conditions. The study also found that the constant energy use, which assumes as a lighting energy consumption, is 5.87–7.78 W/m² or 15.22–20.17 kWh/m² per year.

This review paper treats critical excitation methods and discusses the possibility of a paradigm shift in nonlinear structural dynamics for building structures with hysteresis using input model transformation without structural model transformation. Long-term key issues in the earthquake-resistant design of building structures are combats with resonance and damping. Nonlinear resonance problems are reformulated as critical excitation problems for elastic–plastic structures under a simple impulse sequence. The double impulse (DI) with two impulses of opposite directions is introduced as a simple representative model of near-fault pulse-type ground motions. The interval of such impulses is treated as a parameter to derive the critical input. Another critical excitation problem is considered for elastic–plastic building structures under the multi impulse (MI) representing long-period, long-duration ground motions. These critical excitation problems are solved by using an energy balance approach between the kinetic energy and the strain-dissipated energy. It is pointed out that this paradigm shift enables a smart capture of nonlinear resonance in structural dynamics, which has been thought to need intrinsic repetition of numerical computation. It is also found that this paradigm shift fills a gap between two historical hypotheses (constant energy criterion, constant displacement criterion) in the earthquake-resistant design of building structures.

This data paper presents data obtained from E-Defense shake-table tests of a full-scale, steel moment-resisting frame (MRF) supplemented with Spines. Herein, the Spines were pin-based columns with sufficient stiffness and strength to distribute plastic deformation evenly over the height of the MRF. The specimen was tested under two configurations: first, with the Spine rigidly connected to the MRF; second, with the Spine connected to the MRF through force-limiting connections (FLCs). Each specimen configuration underwent earthquake simulations using ground motions with two scale factors. The tests demonstrated the expected benefits of Spines as well as the disadvantage of inducing large floor accelerations in the structure and large shear forces in the Spines. The tests also demonstrated how the FLCs can mitigate these disadvantages. This data paper reports an overview of the tests, data archive structure, and potential use of the data. The data can be used, for example, to reproduce the observations presented by the authors, to compare the dynamic response of the specimen with building specimens tested in other shake-table test programs, to validate numerical models against the measured specimen response, or to formulate classroom exercises on system identification of linear and nonlinear systems.

Curved origami attracts the attention of designers in recent years for the potential in the field of building structures for free form curved design. For practical use, the design methods are required to link the mathematically obtained curved surface and the requirements of architectural functions. Therefore, in this paper, we propose a method to solve the shape determination problem from predefined developable surfaces described by initial rulings. The initial rulings can be conical or cylindrical surfaces. By means of inputting the ruling lengths, the 3D configuration of the origami model can be obtained. To decrease the number of unknowns, the ruling lengths are mapped by control points of Non-Uniform Rational B-Spline (NURBS) techniques. The numerical example demonstrates the feasibility of finding curved origami with both dome-like and saddle-shaped surfaces and tubular models. This research focuses on the application to architectural engineering, aiming to determine the shape of curved origami using bending deformation to explore the possibility of applying curved origami to building structures.

In order to measure external approaching wind velocity and direction for controlling natural ventilation (NV), anemometers are often installed at the roof top of mid- to high-rise buildings. However, due to the complex flow field around roof top caused by separation flow, the accuracy of the measurement is not well-known. The final goal of this research is to propose an advanced method for controlling NV operation. By conducting PIV and CFD, the results of the accuracy of estimation of external wind direction and velocity at measuring points based on the data regarding horizontal distribution are shown in this paper.