scholarly journals Application of Modal-Displacement Based Design Method to Multi-Story Timber Blockhaus Structures

2020 ◽  
Vol 10 (11) ◽  
pp. 3889
Author(s):  
Martina Sciomenta ◽  
Vincenzo Rinaldi ◽  
Chiara Bedon ◽  
Massimo Fragiacomo
Keyword(s):  
Design Method ◽  
Fe Model ◽  
Structural Elements ◽  
Base Shear ◽  
Shear Loads ◽  
Story Drift ◽  
Displacement Based ◽  
Technical Interest ◽  
Wooden Structures

Structures under seismic excitation undergo different inter-story drift levels that can be associated to damage of both structural and non-structural elements, and thus to the expected losses. The Modal-Displacement Based Design (DBD) procedure, in this regard, has been developed to fix major issues of Force Based Design (FBD) approaches, thus to design multi-story buildings in which the inter-story drift can allow one to control damage mechanisms. In this paper, the conventional Modal-DBD methodology is applied to multi-story timber buildings constructed using the Blockhaus technology. Given their intrinsic geometrical and mechanical features (i.e., stacking of logs, door/window openings, gaps and friction mechanisms, etc.), dedicated methods of analysis are required for them, compared to other wooden structures. A three-story case-study Blockhaus system of technical interest is thus presented for the assessment of Modal-DBD calculation steps. As shown, special care must be spent for the selection of convenient inter-story drift limits that in general should reflect the characteristics of the examined structural typology. The backbone parameters are thus collected for each shear-wall composing the 3D Blockhaus building, based on refined Finite Element (FE) analyses of separate log-walls. The overall results of the Modal-DBD process are thus finally assessed by means of a Push-Over (PO) analysis, carried out on a simplified 3D FE model of the examined multi-story structure. The comparison of FE predictions, as shown, demonstrates that reliable estimates can be obtained when the Modal-DBD procedure is applied to timber Blockhaus systems. In particular, base shear loads can be estimated with good accuracy, while the corresponding top displacements are slightly overestimated (with up to +10%–14% the expected values, for the collapse prevention performance level).

scholarly journals Numerical Study of Alternative Seismic-Resisting Systems for CLT Buildings

Buildings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 162 ◽  
Author(s):  
Cristiano Loss ◽  
Stefano Pacchioli ◽  
Andrea Polastri ◽  
Daniele Casagrande ◽  
Luca Pozza ◽  
...  
Keyword(s):  
Numerical Study ◽  
High Capacity ◽  
Shear Walls ◽  
Sustainable Urban Development ◽  
Fe Model ◽  
Base Shear ◽  
Interior Space ◽  
Linear Dynamic ◽  
Story Drift ◽  
Uplift Forces

Changes to building codes that enable use of materials such as cross-laminated timber (CLT) in mid- and high-rise construction are facilitating sustainable urban development in various parts of the world. Keys to this are the transition to multi-performance-based design approaches along with fewer limitations on heights or the number of storeys in superstructures constructed from combustible materials. Architects and engineers have increased freedom to apply new design and construction concepts and methods, as well as to combine timber with other structural materials. They also have started to develop wall arrangements that optimise interior space layouts and take advantage of the unique characteristics of CLT. This paper discusses the seismic response of multi-story buildings braced with a CLT core and perimeter shear walls anchored to foundations and floor platforms using modern high-capacity angle brackets and hold-downs, or X-Rad connectors. Linear dynamic finite element (FE) models of seismic responses of superstructures of various heights are presented, based on experimentally determined characteristics of wall anchor connections. Particular attention is given to fundamental vibration periods, base shear and uplift forces on walls, as well as inter-story drift. Discussion of FE model results focuses on structural engineering implications and advantages of using CLT to create shear walls, with emphasis on how choice of wall anchoring connections impacts the possible number of storeys and configurations of superstructures. Employing CLT shear walls with X-Rad or other types of high capacity anchoring connections makes possible the creation of building superstructures having eight and potentially more storeys even in high seismicity regions. However, it is important to emphasise that proper selection of suitable arrangements of shear walls for CLT buildings depends on accurate representation of the semi-rigid behaviors of anchoring connections. The linear dynamic analyses presented here demonstrates the need during engineering seismic design practices to avoid use of FE or other design models which do not explicitly incorporate connection flexibilities while estimating parameters like fundamental periods, base shear and uplift forces, as well as inter-story drift.

Topological interlocking in architecture: A new design method and computational tool for designing building floors

2017 ◽  
Vol 15 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Michael Weizmann ◽  
Oded Amir ◽  
Yasha Jacob Grobman
Keyword(s):  
Design Process ◽  
Architectural Design ◽  
Design Method ◽  
Structural Systems ◽  
Two Dimensional ◽  
Structural Elements ◽  
Computational Tool ◽  
Topological Interlocking ◽  
Further Development

This article presents a framework for the design process of structural systems based on the notion of topological interlocking. A new design method and a computational tool for generating valid architectural topological interlocking geometries are discussed. In the heart of the method are an algorithm for automatically generating valid two-dimensional patterns and a set of procedures for creating several types of volumetric blocks based on the two-dimensional patterns. Additionally, the computational tool can convert custom sets of closed planar curves into structural elements based on the topological interlocking principle. The method is examined in a case study of a building floor. The article concludes with discussions on the potential advantages of using the method for architectural design, as well as on challenging aspects of further development of this method toward implementation in practice.

scholarly journals Comparative Study of Direct Displacement Based and Forced Based Design Method for RC- Frame with Shear Wall

10.29007/lft5 ◽  
2018 ◽  
Author(s):  
Bijal Chaudhri ◽  
Dipali Patel
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Shear Wall ◽  
Performance Based Design ◽  
Rc Frame ◽  
Base Shear ◽  
Global Parameter ◽  
Direct Displacement Based Design ◽  
Moment Resisting ◽  
Displacement Based

The Seismic design of structure has conventionally been force based. Displacement is the major factor for the damage rather than force. The alternative procedure for seismic design, which becomes more popular, is performance based design method. Displacement is global parameter of performance based design method. Direct displacement based design method has been used for seismic design of structure. The paper attempts to design moment resisting RC-frame using Displacement based design method and Forced based design method. 15-storey building with shear wall has been taken for parametric study. The parameter like base shear and lateral load distribution are taken for the study. It is observed that base shear of RC building calculated by DDBD is less compared to FBD.

A Direct Displacement-Based Design Method Based on Chinese Code of Base Isolated Structures

2011 ◽  
Vol 255-260 ◽  
pp. 2555-2559
Author(s):  
Zhen Sun ◽  
Wei Qing Liu ◽  
Shu Guang Wang ◽  
Ding Zhou ◽  
Dong Sheng Du
Keyword(s):  
Seismic Isolation ◽  
Design Method ◽  
Response Spectrum ◽  
Base Shear ◽  
Direct Displacement Based Design ◽  
High Intensity Zone ◽  
Lead Rubber Bearings ◽  
Displacement Based ◽  
Rubber Bearings ◽  
Relationship Of

A simple and efficient direct displacement-based design (DDBD) method is introduced to base isolated (BI) structures. Assuming the vibration mode of superstructure to be the shear type and considering the BI structure to be an equivalent single degree of freedom (ESDOF) system with spring and damper at the seismic isolation layer. The acceleration response spectrum in Chinese code is converted to displacement response spectrum. Corresponding to the design displacement, the equivalent period is obtained. The relationship of the deign displacement, equivalent period, equivalent stiffness and base shear of the system can be derived from the given formulations. Then, the distribution of the base shear along the floors is obtained. This method has been applied to the design of a 12-story BI structure with lead rubber bearings in high intensity zone in Suqian city, Jiangsu province. The results show that the method is feasible for the design of BI structures.

Parametric Analysis and Direct Displacement-Based Design Method of Self-Centering Energy-Dissipative Steel-Braced Frames

2017 ◽  
Vol 17 (08) ◽  
pp. 1750087 ◽  
Author(s):  
Qin Xie ◽  
Zhen Zhou ◽  
Canjun Li ◽  
Shaoping Meng
Keyword(s):  
Design Method ◽  
Residual Deformation ◽  
Design Parameters ◽  
Equivalent Linearization ◽  
Braced Frames ◽  
Braced Frame ◽  
Direct Displacement Based Design ◽  
Story Drift ◽  
Displacement Based ◽  
Nonlinear Dynamic Analyses

The self-centering energy-dissipative (SCED) brace is a novel bracing element that can substantially reduce the residual deformation and enhance the reparability of structures. In this paper, nonlinear dynamic analyses have been conducted on a 4- and a 12-story steel-braced frame with SCED braces to study the effect of four important design parameters on the seismic performance of the SCED frames and recommendations are given for selection of the parameters. The parameters considered include the response modification coefficient [Formula: see text], the stiffness ratio of the brace [Formula: see text], the strength ratio of the brace [Formula: see text], and the fuse activation story drift [Formula: see text]. The relationship between the residual story drift and the peak story drift of the SCED frames is obtained based on these statistics. Finally, based on the equivalent linearization theory, a direct displacement-based design method applicable to the SCED frames, regarding both the peak story drift and residual story drift as the design objectives, is proposed.

PERANCANGAN SISTEM PEMBELAJARAN MOBILE (M-LEARNING) BERBASIS ANDROID PADA MATERI BANGUN DATAR DAN BANGUN RUANG

2018 ◽  
Vol 1 (2) ◽  
pp. 1-17
Author(s):  
Tedi Budiman
Keyword(s):  
Mobile Learning ◽  
Design Method ◽  
Case Study Method ◽  
Application Development ◽  
Software Application ◽  
Rapid Application Development ◽  
User Design ◽  
Design Software ◽  
Application Programs

One example of the growing information technology today is mobile learning, mobile learning which refers to mobile technology as a learning medium. Mobile learning is learning that is unique for each student to access learning materials anywhere, anytime. Mobile learning is suitable as a model of learning for the students to make it easier to get an understanding of a given subject, such as math is pretty complicated and always using formulas.The design method that I use is the case study method, namely, learning, searching and collecting data related to the study. While the development of engineering design software application programs that will be used by the author is the method of Rapid Application Development (RAD), which consists of 4 stages: Requirements Planning Phase, User Design Phase, Construction Phase and Phase Cotuver.

scholarly journals Effect of blast loading and resulting progressive failure of a cable-stayed bridge

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Ravi Mudragada ◽  
S. S. Mishra
Keyword(s):  
Progressive Failure ◽  
Blast Resistance ◽  
Progressive Collapse ◽  
Building Structures ◽  
Structural Elements ◽  
Blast Loads ◽  
Cable Stayed Bridge ◽  
Bridge Performance ◽  
Cable Stayed Bridges

AbstractMany researchers have carried out experimental and numerical investigations to examine building structures’ response to explosive loads. Studies of bridges subjected to blast loads are limited. Hence, in this study, we present a case study on a cable-stayed bridge, namely, Charles River Cable-Stayed Bridge-Boston, to assess its robustness and resistance against the progressive collapse resulting from localized failure due to blast loads. Three different blast scenarios are considered to interpret the bridge performance to blast loads. To monitor the progressive failure mechanisms of the structural elements due to blast, pre-defined plastic hinges are assigned to the bridge deck. The results conclude that the bridge is too weak to sustain the blast loads near the tower location, and the progressive collapse is inevitable. Hence, to preserve this cable-stayed bridge from local and global failure, structural components should be more reinforced near the tower location. This case study helps the designer better understand the need for blast resistance design of cable-stayed bridges.

scholarly journals Stability charts based on the finite element method for underground cavities in soft carbonate rocks: validation through case-study applications

2019 ◽  
Vol 19 (10) ◽  
pp. 2079-2095 ◽  
Author(s):  
Michele Perrotti ◽  
Piernicola Lollino ◽  
Nunzio Luciano Fazio ◽  
Mario Parise
Keyword(s):  
Finite Element ◽  
Safety Margin ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Geometrical Features ◽  
Overall Stability ◽  
Underground Cavities ◽  
The Stability ◽  
Rock Mechanical Properties

Abstract. The stability of man-made underground cavities in soft rocks interacting with overlying structures and infrastructures represents a challenging problem to be faced. Based upon the results of a large number of parametric two-dimensional (2-D) finite-element analyses of ideal cases of underground cavities, accounting for the variability both cave geometrical features and rock mechanical properties, specific charts have been recently proposed in the literature to assess at a preliminary stage the stability of the cavities. The purpose of the present paper is to validate the efficacy of the stability charts through the application to several case studies of underground cavities, considering both quarries collapsed in the past and quarries still stable. The stability graphs proposed by Perrotti et al. (2018) can be useful to evaluate, in a preliminary way, a safety margin for cavities that have not reached failure and to detect indications of predisposition to local or general instability phenomena. Alternatively, for sinkholes that already occurred, the graphs may be useful in identifying the conditions that led to the collapse, highlighting the importance of some structural elements (as pillars and internal walls) on the overall stability of the quarry system.

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