Dynamic analysis of a historical monument: retrofit using shape memory alloy wires

Hamdaoui, Karim,Benadla, Zahira Techno-Press 2014 Smart Structures and Systems, An International Jou Vol.13 No.3

The effectiveness of using the advanced seismic protection technology based on shape memory alloy (SMA) dampers to preserve a historical minaret is investigated. The proposed studied case, the minaret of Mansourah, is a seven century old minaret located in Tlemcen, Algeria. Its original height was of 47m, while nowadays, the monument is half destructed and its current height reaches the 40m. The proposed seismic retrofit is based on the technique that utilizes SMA wires as dampers for the upper flexible part of the minaret. The effectiveness of the proposed technique is numerically evaluated via non-linear finite element analysis using the structural software ANSYS. The effectiveness of the proposed device in mitigating the seismic hazard is demonstrated by the effective reduction in its dynamic response.

Dynamic analysis of a historical monument: retrofit using shape memory alloy wires

Karim Hamdaoui,Zahira Benadla 국제구조공학회 2014 Smart Structures and Systems, An International Jou Vol.13 No.3

The effectiveness of using the advanced seismic protection technology based on shape memoryalloy (SMA) dampers to preserve a historical minaret is investigated. The proposed studied case, the minaretof Mansourah, is a seven century old minaret located in Tlemcen, Algeria. Its original height was of 47m,while nowadays, the monument is half destructed and its current height reaches the 40m. The proposedseismic retrofit is based on the technique that utilizes SMA wires as dampers for the upper flexible part ofthe minaret. The effectiveness of the proposed technique is numerically evaluated via non-linear finiteelement analysis using the structural software ANSYS. The effectiveness of the proposed device inmitigating the seismic hazard is demonstrated by the effective reduction in its dynamic response.

Dynamic behavior of a seven century historical monument reinforced by shape memory alloy wires

Karim Hamdaoui,Zahira Benadla,Houssameddine Chitaoui,Mohammed Elamine Benallal 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.23 No.4

This work resumes a research that proposes the use of the technique based on the dissipation energy of the shape memory alloy (SMA) ties. It focuses principally on the assessment of the effectiveness of the use of these smart materials on displacements, accelerations and the stresses of the minaret of the great mosque of Ajloun in Jordan. The 3-D finite element model of the minaret is performed by the ANSYS software. First of all, the proposed model is calibrated and validated according to the experimental results gathered from ambient vibration testing results. Then, a nonlinear transient analysis is considered, when the El-Centro earthquake is used as the input signal. Different simulating cases concerning the location, number and type of SMA devices are proposed in order to see their influence on the seismic response of the minaret. Hence, the results confirm the effectiveness of the proposed SMA device.

Liberalization, Regulatory Delays and Vulnerability to Systemic Banking Crisis

Mekki Hamdaoui 한국국제경제학회 2017 International Economic Journal Vol.31 No.4

This work aims at contributing to the improvement of the early warning systems of banking crises using a new approach accounting for model uncertainty. We show that a multinomial logit model based on Bayesian model averaging (BMA) is a good strategy to predict banking crisis. To do this, we argue that differences in vulnerability to banking crisis can be largely explained by an asymmetry between financial market evolution and regulation update on a sample of 49 developed and developing countries between 1980 and 2010. When markets are liberalized, competition pushes bankers to take more risks and take advantage of regulatory delays thus increasing crises probabilities. Our empirical evidence supports that crisis probability is higher in country liberalizing their banking system when regulation is not updated. We developed an early warning system for systemic banking crises based on the multinomial logit model. Its main difference to existing prediction models and its contribution to the literature is that it is intended to identify and resolve what is called by Bussiere and Fratzscher [(2006). Towards a new early warning system of financial crises. Journal of International Money and Finance, 25(6), 953–973] as post-crisis bias in binomial models and to develop a new methodology of leading indicators selection based on BMA. Overall, our model predicts all banking crises during our sample period.

Experimental and numerical studies toward the implementation of shape memory alloy ties in masonry structures

Casciati, Sara,Hamdaoui, Karim Techno-Press 2008 Smart Structures and Systems, An International Jou Vol.4 No.2

The use of pre-tensioned shape memory alloy (SMA) wires to retrofit historic masonry structures is investigated. A small wall, serving as a prototype masonry specimen, is constructed to undergo a series of shaking-table tests. It is first studied in its original state, and its dynamic characteristics (in terms of modal frequencies) are extracted from the recorded signals. The results are then compared with those obtained when an increasing number of couples of pre-stressed SMA wires are introduced in the specimen to link the bricks together. A three-dimensional finite element model of the specimen is developed and calibrated according to the modal parameters identified from each experimental test (with and without SMA wires). The calibration process is conducted by enhancing the masonry mechanical behaviour. The results and the effectiveness of the approach are presented.

Inequality of Opportunity and Degree of Human Development: Evidence from Tunisia

Saidi Anis,Hamdaoui Mekki,Ochi Anis 중앙대학교 경제연구소 2021 Journal of Economic Development Vol.46 No.1

There are many socio-economic factors beyond the individual control that can affect human development indicators. In this setting, this paper aims to examine the effects and evolution of unequal opportunities on the distribution of human development indicators embodied by monetary well-being (consumption) and education in Tunisia for the period 2005-2010. We used parametric and non-parametric approach in addition to Dissimilarity-Index and Shapley’s Decomposition to identify most important factors explaining inequality of chances in Tunisia. We found that Father’s education, residence area, and connection to drinking water appears to be the most important background variables affecting well-being profile. However, child’s sex appears to be the most important determinant of the accessibility to education. Inequality of opportunity in consumption and education persists and tends to increase over time which is undesirable for the country. As an economic implication of our results, policy makers must make appropriate policies to reduce intergenerational transmission of parental background and sex discrimination and to overcome traps of inequality for future generations

Does Regime Choice Affect Exchange Rate Volatility-Economic Growth Link? An Application of Panel-VAR Approach

Salma Haj fraj,hamdaoui, Mekki,Maktouf, Samir 한국국제경제학회 2018 International Economic Journal Vol.32 No.1

In recent years, numerous studies demonstrated that the effect of exchange rate regimes on economic growth is influenced by several factors. However, the literature rarely takes into account the possible costs associated with improving institutional quality on the choice of exchange systems and the analysis of the effects of shocks in the case of each type of regime. Throughout this research, we analyze the extent of bidirectional shocks according to each regime and compare the shock effects accordingly. The results show that the real exchange rate is less volatile and the shock effect is lower in countries that adopt a fixed exchange rate regime while the exchange rate is more volatile and the shock is higher in countries that adopt a flexible exchange rate regime. To show the effect and persistence of shocks, we carried out a Panel-VAR regression completed by impulse response functions, VAR decomposition and Granger causality tests for 20 countries adopting the first type of exchange regime compared with 20 countries practicing an alternative exchange rate regime in the period from 1996 to 2012.

Extraction of endocrine disrupting compound propylparaben from water by emulsion liquid membrane using trioctylphosphine oxide as carrier

Sarah Chaouchi,Oualid Hamdaoui 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.22 No.-

The extraction of endocrine disrupting compound propylpraben (PP) from aqueous solution by emulsionliquid membrane was investigated. The ELM contains trioctylphosphine oxide (TOPO) as extractant, nhexaneas solvent and Span 80 as surfactant. Na2CO3 was used as internal aqueous phase. The effects ofoperating parameters for the ELM process were examined. It was possible to perfectly remove all of PPmolecules from the external feed solution by using the best experimental conditions. ELM treatmentprocess represents an efficient advanced separation technique for the removal of PP even from complexmatrices such as natural water, seawater and sewage water effluent.

Preparation and Characterization of Recycled PP/Organo-Clay Filter for Dyeing Ability

Adel Elamri,Mohamed Hamdaoui,Omar Harzallah 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

Organo-modified clay was used to prepare waste polypropylene/clay composite by melt mixing method. Composites were then melt spun into linear filaments. Attention is given to how the organoclay influence the morphologyand the dyeability of resultant waste PP filaments. Scanning electron microscopy was used to investigate the surfacemorphology and cross section of the filaments. Dyeing studies underlined the improvement of dye affinity of elaboratedfilaments to acid, basic, and disperse dyes. Moreover, we observed that waste PP and its composite monofilaments have thehighest dyeability when using disperse dye. The prepared filaments were then used to fulfill a filter for the treatment of textiledye waste water. Thus, 3D geometrical design of the filter structure was realized by the SolidWorks mechanical designsoftware.

Experimental and numerical studies toward the implementation of shape memory alloy ties in masonry structures

Sara Casciati,Karim Hamdaoui 국제구조공학회 2008 Smart Structures and Systems, An International Jou Vol.4 No.2

The use of pre-tensioned shape memory alloy (SMA) wires to retrofit historic masonry structures is investigated. A small wall, serving as a prototype masonry specimen, is constructed to undergo a series of shakingtable tests. It is first studied in its original state, and its dynamic characteristics (in terms of modal frequencies) are extracted from the recorded signals. The results are then compared with those obtained when an increasing number of couples of pre-stressed SMA wires are introduced in the specimen to link the bricks together. A threedimensional finite element model of the specimen is developed and calibrated according to the modal parameters identified from each experimental test (with and without SMA wires). The calibration process is conducted by enhancing the masonry mechanical behaviour. The results and the effectiveness of the approach are presented.