scholarly journals Seismic vulnerability of the Himalayan half-dressed rubble stone masonry structures, experimental and analytical studies

2012 ◽  
Vol 12 (11) ◽  
pp. 3441-3454 ◽  
Author(s):  
N. Ahmad ◽  
Q. Ali ◽  
M. Ashraf ◽  
B. Alam ◽  
A. Naeem
Keyword(s):  
Experimental Study ◽  
Seismic Vulnerability ◽  
Structural Model ◽  
Dynamic Properties ◽  
Lateral Force ◽  
Constitutive Law ◽  
Stone Masonry ◽  
Masonry Structures ◽  
Vibration Period ◽  
Analytical Studies

Abstract. Half-Dressed rubble stone (DS) masonry structures as found in the Himalayan region are investigated using experimental and analytical studies. The experimental study included a shake table test on a one-third scaled structural model, a representative of DS masonry structure employed for public critical facilities, e.g. school buildings, offices, health care units, etc. The aim of the experimental study was to understand the damage mechanism of the model, develop damage scale towards deformation-based assessment and retrieve the lateral force-deformation response of the model besides its elastic dynamic properties, i.e. fundamental vibration period and elastic damping. The analytical study included fragility analysis of building prototypes using a fully probabilistic nonlinear dynamic method. The prototypes are designed as SDOF systems assigned with lateral, force-deformation constitutive law (obtained experimentally). Uncertainties in the constitutive law, i.e. lateral stiffness, strength and deformation limits, are considered through random Monte Carlo simulation. Fifty prototype buildings are analyzed using a suite of ten natural accelerograms and an incremental dynamic analysis technique. Fragility and vulnerability functions are derived for the damageability assessment of structures, economic loss and casualty estimation during an earthquake given the ground shaking intensity, essential within the context of risk assessment of existing stock aiming towards risk mitigation and disaster risk reduction.

Seismic Vulnerability Assessment of Multistory Timber Braced Frame Traditional Masonry Structures

2012 ◽  
Vol 601 ◽  
pp. 168-172 ◽  
Author(s):  
Naveed Ahmad ◽  
Qaisar Ali ◽  
Muhammad Umar
Keyword(s):  
Dynamic Analysis ◽  
Seismic Vulnerability ◽  
Seismic Analysis ◽  
Pushover Analysis ◽  
Elastic Beam ◽  
Lateral Force ◽  
Experimental Results ◽  
Constitutive Law ◽  
Masonry Structures ◽  
Braced Frame

Research carried out on the seismic investigation of timber braced frame (TBF) masonry structures of traditional construction practice is presented, essential for seismic performance evaluation of such construction type using engineering approaches. An innovative simplified equivalent frame method (EFM) based on macro modelling approach is presented for nonlinear dynamic seismic analysis of TBF masonry structures. The modelling include EFM idealization of wall using stiff elastic beam-column element assigned with moment-rotation (M-θ) nonlinear lumped plasticity hinges. Earlier, the approach i.e. the EFM idealization and M-θ constitutive law, is calibrated with the experimental results obtained through quasi-static cyclic test on full scale walls. The technique is further extended herein for seismic dynamic analysis of multistory structures. Generalization of the technique for modelling walls of various geometry and loading is performed. It included nonlinear static pushover analysis of various case study walls, by means of SAP2000 calibrated earlier with experimental results, for the derivation of lateral force-deformability behavior towards the development of generalized M-θ constitutive law for TBF masonry walls. Three representative structures, from one to three storeys, are analyzed using a suite of ten natural accelerograms and incremental dynamic analysis technique. Structure fragility and resilience functions are derived using a fully probabilistic and dynamic approach. The structures analyzed in the present study represent TBF masonry wall structures, called as Dhajji-Dewari structures, common in Northern areas of Pakistan.

Seismic Vulnerability Assessment of Masonry Building from Ottoman Period in Bosnia and Herzegovina

2015 ◽  
pp. 734-764
Author(s):  
Mustafa Hrasnica ◽  
Amir Čaušević ◽  
Nerman Rustempašić
Keyword(s):  
Bosnia And Herzegovina ◽  
Seismic Vulnerability ◽  
Stone Masonry ◽  
Masonry Building ◽  
Masonry Structures ◽  
Historical Buildings ◽  
Traditional Art ◽  
South East Europe ◽  
Structural Engineers ◽  
Scale Design

Traditional art of building in Bosnia and Herzegovina comprises brick or stone masonry structures. Most historical buildings belonging to national cultural heritage were made of stone-masonry. The country is situated in seismic active region of South-East Europe. In the case of strong earthquake motion such buildings could suffer heavy damages. Some structural elements of historical buildings, as domes and arches, cracked already by moderate earthquake but without the loss of stability. Substantial damages were caused by recent war disaster. Damages could be accumulated through the history as well. Generally, stone-masonry buildings in Bosnia and Herzegovina can be classified in vulnerability classes between A and C according to European Macroseismic Scale. Design and construction procedures for rehabilitation are presented here with examples of repair and strengthening of mosques, which present historical stone masonry structures dating from the Ottoman period in Bosnia and Herzegovina. Traditional and contemporary materials were used for their rehabilitation. It is important to preserve original forms, especially those of damaged elements. The challenge for structural engineers and architects was to find equilibrium between aesthetical and structural demands.

Seismic Vulnerability Assessment of Masonry Building from Ottoman Period in Bosnia and Herzegovina

2019 ◽  
pp. 1142-1173
Author(s):  
Mustafa Hrasnica ◽  
Amir Čaušević ◽  
Nerman Rustempašić
Keyword(s):  
Bosnia And Herzegovina ◽  
Seismic Vulnerability ◽  
Stone Masonry ◽  
Masonry Building ◽  
Masonry Structures ◽  
Historical Buildings ◽  
Traditional Art ◽  
South East Europe ◽  
Structural Engineers ◽  
Scale Design

Traditional art of building in Bosnia and Herzegovina comprises brick or stone masonry structures. Most historical buildings belonging to national cultural heritage were made of stone-masonry. The country is situated in seismic active region of South-East Europe. In the case of strong earthquake motion such buildings could suffer heavy damages. Some structural elements of historical buildings, as domes and arches, cracked already by moderate earthquake but without the loss of stability. Substantial damages were caused by recent war disaster. Damages could be accumulated through the history as well. Generally, stone-masonry buildings in Bosnia and Herzegovina can be classified in vulnerability classes between A and C according to European Macroseismic Scale. Design and construction procedures for rehabilitation are presented here with examples of repair and strengthening of mosques, which present historical stone masonry structures dating from the Ottoman period in Bosnia and Herzegovina. Traditional and contemporary materials were used for their rehabilitation. It is important to preserve original forms, especially those of damaged elements. The challenge for structural engineers and architects was to find equilibrium between aesthetical and structural demands.

A Mathematical-physical 3D Tire Model for Handling/Comfort Optimization on a Vehicle: Comparison with Experimental Results

2000 ◽  
Vol 28 (4) ◽  
pp. 210-232 ◽  
Author(s):  
F. Mancosu ◽  
R. Sangalli ◽  
F. Cheli ◽  
G. Ciarlariello ◽  
F. Braghin
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Finite Element Model ◽  
Structural Model ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
Element Model ◽  
Lateral Force ◽  
Tire Model ◽  
Relaxation Length

Abstract A new 3D mathematical-physical tire model is presented. This model considers not only the handling behavior of the tire but also its comfort characteristics, i.e., the dynamic properties in the lateral and the vertical planes. This model can be divided into two parts, the structural model and the contact area model. The structural parameters are identified by comparison with frequency responses of a 3D finite element model of the tire, whereas the contact parameters are directly calculated with a finite element model of the tread pattern. The 3D physical model allows predicting both steady state and transient behavior of the tire without the need of any experimental tests on the tire. The steady state analysis allows obtaining the friction circle diagram, i.e., the plot of the lateral force against the longitudinal force for different slip angles and for longitudinal slip, and the Gough plot, i.e., the diagram of the self-aligning torque versus the lateral force. The transient analysis allows obtaining the dynamic behavior of the tire for any maneuver given to the wheel. Among its outputs there are the relaxation length and the dynamic forces and torque transmitted to the suspension of the vehicle. Combining the tire model with the vehicle model it is possible to perform any kind of maneuver such as overtaking, changing of lane and steering pad at growing speed with or without braking, or accelerating. Therefore the 3D tire model can be seen as a powerful tool to optimize the tire characteristics through a sensitivity analysis performed with tire and vehicle models linked to each other without the need of building prototypes. Some preliminary comparisons with experimental data have been carried out.

Experimental Study of Steel Strips-Strengthened Masonry Panels

2013 ◽  
Vol 838-841 ◽  
pp. 297-307
Author(s):  
Pei Chi ◽  
Bei Bei Wang ◽  
Hai Feng Bo ◽  
Yang Peng ◽  
Jun Dong
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Seismic Vulnerability ◽  
Masonry Wall ◽  
Crack Pattern ◽  
Lateral Loading ◽  
Lateral Stiffness ◽  
Masonry Structures ◽  
Steel Strips ◽  
Ultimate Displacement

Because of the seismic vulnerability of these masonry structures, many strengthened technologies for improving their its seismic performance of masonry panels have been improved in old days. In this paper, a rapid strengthening approach of masonry structures which is diagonal steel strips attached to the masonry panels is proposed. To investigate crack pattern, shear strength, lateral stiffness and ultimate displacement, four Specimens constructed at with 1:2 scale are designed. One specimen was not strengthened by steel strips, and the others strengthen by steel strips with different width and thickness. They are tested under combined constant vertical compression and cyclic lateral loading. The experimental results prove that reinforcement approach could a changed crack pattern. Also, it could significantly increase in the shear strength and lateral stiffness of masonry panels. The width of steel strips is more significant than the thickness of steel strips in strengthening shear strength and lateral stiffness of masonry wall.

A simulation apparatus for the experimental study of batch reactor control methods

1986 ◽  
Vol 51 (6) ◽  
pp. 1259-1267
Author(s):  
Josef Horák ◽  
Petr Beránek
Keyword(s):  
Experimental Study ◽  
Closed Loop ◽  
Dynamic Properties ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Electric Heating ◽  
Batch Reactors ◽  
Exchange Area ◽  
The Stability ◽  
Methods Of Control

A simulation apparatus for the experimental study of the methods of control of batch reactors is devised. In this apparatus, the production of heat by an exothermic reaction is replaced by electric heating controlled by a computer in a closed loop; the reactor is cooled with an external cooler whose dynamic properties can be varied while keeping the heat exchange area constant. The effect of the cooler geometry on its dynamic properties is investigated and the effect of the cooler inertia on the stability and safety of the on-off temperature control in the unstable pseudostationary state is examined.

Experimental Study of Adhesion between FRCM and Masonry Support

2014 ◽  
Vol 624 ◽  
pp. 189-196 ◽  
Author(s):  
Valeria Corinaldesi ◽  
Jacopo Donnini ◽  
Giorgia Mazzoni
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Bond Strength ◽  
Cement Matrix ◽  
Masonry Structures ◽  
Matrix Interface ◽  
Mechanical Interaction ◽  
Inorganic Particles ◽  
Ceramic Support

The use of composites with cement matrix seems to acquire an increasing interest in applications to masonry structures, due to their low impact, and a deeper understanding of the mechanical interaction between support and reinforcement is certainly necessary. The effectiveness of these interventions strongly depends on the bond between strengthening material and masonry, on the fibers/matrix interface, as well as on the mechanical properties of the masonry substrate [1]. In this work the attention was focused on the possible improvement of the bond between FRCM and masonry by means of an inorganic primer, which can be spread on the ceramic support before the application of FRCM reinforcement. Two different kinds of brick were tested, in order to simulate more or less porous masonry supports. Results obtained showed that, independently on the kind of brick used (more or less porous) the presence of an inorganic primer always improves bond between masonry support and the cementitiuos matrix of FRCM. In fact, the cementitous matrix of FRCM has been studied and optimized in order to guarantee the best fibers/matrix interface, while it is not necessarily the best option for improving the adhesion with the masonry support. In particular, very effective seems to be the use of very fine inorganic particles (at nanometric scale), which proved to be able to assure the best results in terms of bond strength. Also the fresh consistence of the primer seemed to influence the final result.

Experimental study on seismic performance of suspended ceiling components

2021 ◽  
Author(s):  
Yong Wang ◽  
Huanjun Jiang ◽  
Chen Wu ◽  
Zihui Xu ◽  
Zhiyuan Qin
Keyword(s):  
Experimental Study ◽  
Energy Dissipation ◽  
Seismic Performance ◽  
Seismic Vulnerability ◽  
Axial Loading ◽  
Deformation Capacity ◽  
Severe Damage ◽  
Strong Earthquakes ◽  
Static Tests ◽  
Load Carrying

<p>Suspended ceiling systems (SCSs) experienced severe damage during strong earthquakes that occurred in recent years. The capacity of the ceiling component is a crucial factor affecting the seismic performance of SCS. Therefore, a series of static tests on suspended ceiling components under monotonic and cyclic loadings were carried out to investigate the seismic performance of the ceiling components. The ceiling components include main tee splices, cross tee latches and peripheral attachments. All specimens were tested under axial loading. Additionally, the static tests of cross tee latches subjected to shear and bending loadings were performed due to their seismic vulnerability. The failure pattern, load-carrying ability, deformation capacity and energy dissipation of the ceiling components are presented in detail in this study.</p>

Correlation Study on Modal Frequency and Temperature Effects of a Cable-Stayed Bridge Model

2012 ◽  
Vol 446-449 ◽  
pp. 3264-3272 ◽  
Author(s):  
Li Min Sun ◽  
Yi Zhou ◽  
Xue Lian Li
Keyword(s):  
Experimental Study ◽  
Boundary Conditions ◽  
Dynamic Properties ◽  
Bridge Engineering ◽  
Fe Model ◽  
Steel Cable ◽  
Transverse Beam ◽  
Expansion Joints ◽  
Cable Stayed Bridge ◽  
Bridge Model

In recent years, structural health monitoring has been paid more and more attention in bridge engineering community. Previous researches showed that ambient temperature was one of principal factors affecting structural modal parameters in long-term. In this paper, an experimental study on correlation between dynamic properties of a cable-stayed bridge and its structural temperature was performed under temperature controlled laboratory environment. Using hammer impacting method, a dynamic testing was conducted based on a steel cable-stayed bridge model which had a span layout of 0.9+1.9+0.9m. During the experiment, the first six vertical bending modes under the environmental temperature of 0, 20 and 40°C were identified with the consideration of three kinds of boundary conditions at the deck’s ends as to two degrees of freedom, i.e. the longitudinal translation (UX) and the rotation about the transverse beam (RotZ). The above boundary conditions are UX & RotZ not constrained, UX constrained only and UX & RotZ constrained, attempting to simulate the different conditions of the bridge expansion joints. The efforts were paid to explain the physical mechanism of the results based on the updated FE model. This experimental study indicates a tendency that the frequency of the cable-stayed bridge model decreases with the increase of temperature. And furthermore, the relative difference of frequencies between 0 and 40 °C is affected by boundary conditions; in other words, when the deck is free to expand, the variation of model’s frequencies is smaller than that when the deck is restrained to expand, which is similar to the condition of the bridge’s expansion joints cannot work as normal. This experimental study can give some reference to the research of SHM and damage identification for cable-stayed bridges.

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