• Title/Summary/Keyword: structural performance indices

Search Result 99, Processing Time 0.026 seconds

Factors Influencing Business Performance of Small and Medium Enterprises: A Case Study in Sri Lanka

  • SALFIYA UMMAH, Mohamed Abdul Cader;CHOY, Chong Siong;SULAIHA BEEVI, Athambawa
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.8 no.4
    • /
    • pp.201-212
    • /
    • 2021
  • This study aims to investigate variables affecting the business performance of Muslim women entrepreneurs in Sri Lanka. A multidimensional analysis was proposed with five potentially defined antecedents of business performance which included psychological characteristics, human capital, social capital, industrial factor, and cultural factor. Data was collected from 286 respondents through the use of a self-administered questionnaire. The results of structural equation modeling indicate that the model meets the goodness-of-fit indices and that generally, all five factors have significant positive relationships with business performance. Amongst the dimensions of psychological characteristics, only risk-taking had a notable effect on business performance. Amongst the dimensions of human capital, two of the three dimensions (business experience and business skills) were significantly associated with business performance; in the case of social capital, one of the two dimensions (non-familial affiliations) was significantly associated with business performance; and in the case of industrial factor, resource accessibility was significantly associated with business performance. A strong positive correlation with business performance has also been demonstrated by the cultural factor which was a new concept to the paradigm as a whole. This study has broadened the understanding of existing literature on Muslim women entrepreneurship and contributed practical implications to government, policymakers and other related agencies, chambers of commerce, the general public, as well as the Muslim women entrepreneurs themselves.

Remaining service life estimation of reinforced concrete buildings based on fuzzy approach

  • Cho, Hae-Chang;Lee, Deuck Hang;Ju, Hyunjin;Kim, Kang Su;Kim, Ki-Hyun;Monteiro, Paulo J.M.
    • Computers and Concrete
    • /
    • v.15 no.6
    • /
    • pp.879-902
    • /
    • 2015
  • The remaining service life (RSL) of buildings has been an important issue in the field of building and facility management, and its development is also one of the essential factors for achieving sustainable infrastructure. Since the estimation of RSL of buildings is heavily affected by the subjectivity of individual inspector or engineer, much effort has been placed in the development of a rational method that can estimate the RSL of existing buildings more quantitatively using objective measurement indices. Various uncertain factors contribute to the deterioration of the structural performance of buildings, and most of the common building structures are constructed not with a single structural member but with various types of structural components (e.g., beams, slabs, and columns) in multistory floors. Most existing RSL estimation methods, however, consider only an individual factor. In this study, an estimation method for RSL of concrete buildings is presented by utilizing a fuzzy theory to consider the effects of multiple influencing factors on the deterioration of durability (e.g., concrete carbonation, chloride attack, sulfate attack), as well as the current structural condition (or damage level) of buildings.

Reliability-based assessment of damaged concrete buildings

  • Sakka, Zafer I.;Assakkaf, Ibrahim A.;Qazweeni, Jamal S.
    • Structural Engineering and Mechanics
    • /
    • v.65 no.6
    • /
    • pp.751-760
    • /
    • 2018
  • Damages in concrete structures due to aging and other factors could be a serious and immense matter. Making the best selection of the most viable and practical repairing and strengthening techniques are relatively difficult tasks using traditional methods of structural analyses. This is due to the fact that the traditional methods used for assessing aging structure are not fully capable when considering the randomness in strength, loads and cost. This paper presents a reliability-based methodology for assessing reinforced concrete members. The methodology of this study is based on probabilistic analysis, using statistics of the random variables in the performance function equations. Principles of reliability updating are used in the assessment process, as new information is taken into account and combined with prior probabilistic models. The methodology can result in a reliability index ${\beta}$ that can be used to assess the structural component by comparing its value with a standard value. In addition, these methods result in partial safety factor values that can be used for the purpose of strengthening the R/C elements of the existing structure. Calculations and computations of the reliability indices and the partial safety factors values are conducted using the First-order Reliability Method and Monte Carlo simulation.

Fragility analysis of R/C frame buildings based on different types of hysteretic model

  • Borekci, Muzaffer;Kircil, Murat S.
    • Structural Engineering and Mechanics
    • /
    • v.39 no.6
    • /
    • pp.795-812
    • /
    • 2011
  • Estimation of damage probability of buildings under a future earthquake is an essential issue to ensure the seismic reliability. Fragility curves are useful tools for showing the probability of structural damage due to earthquakes as a function of ground motion indices. The purpose of this study is to compare the damage probability of R/C buildings with low and high level of strength and ductility through fragility analysis. Two different types of sample buildings have been considered which represent the building types mentioned above. The first one was designed according to TEC-2007 and the latter was designed according to TEC-1975. The pushover curves of sample buildings were obtained via pushover analyses. Using 60 ground motion records, nonlinear time-history analyses of equivalent single degree of freedom systems were performed using bilinear hysteretic model and peak-oriented hysteretic model with stiffness - strength deterioration for each scaled elastic spectral displacement. The damage measure is maximum inter-story drift ratio and each performance level considered in this study has an assumed limit value of damage measure. Discrete damage probabilities were calculated using statistical methods for each considered performance level and elastic spectral displacement. Consequently, continuous fragility curves have been constructed based on the lognormal distribution assumption. Furthermore, the effect of hysteresis model parameters on the damage probability is investigated.

Application of Sliding Mode Fuzzy Control with Disturbance Estimator to Benchmark Problem for Wind Excited Building (풍하중을 받는 벤치마크 구조물의 진동제어를 위한 외란 예측기가 포함된 슬라이딩 모드 퍼지 제어)

  • Kim, Saang-Bum;Yun, Chung-Bang;Gu, Ja-In
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2000.06a
    • /
    • pp.246-250
    • /
    • 2000
  • A distinctive feature in vibration control of a large civil infrastructure is the existence of large disturbances, such as wind, earthquake, and sea wave forces. Those disturbances govern the behavior of the structure, however, they cannot be precisely measured, especially for the case of wind-induced vibration control. The sliding mode fuzzy control (SMFC), which is of interest in this study, may use not only the structural response measurement but also the wind force measurement. Hence, an adaptive disturbance estimation filter is introduced to generate a wind force vector at each time instance based on the measured structural response and the stochastic information of the wind force. The structure of the filter is constructed based on an auto-regressive with auxiliary input model. A numerical simulation is carried out on a benchmark problem of a wind-excited building. The results indicate that the overall performance of the proposed SMFC is as good as the other methods and that most of the performance indices improve as the adaptive disturbance estimation filter is introduced.

  • PDF

A modified replacement beam for analyzing building structures with damping systems

  • Faridani, Hadi Moghadasi;Capsoni, Antonio
    • Structural Engineering and Mechanics
    • /
    • v.58 no.5
    • /
    • pp.905-929
    • /
    • 2016
  • This paper assesses efficiency of the continuum method as the idealized system of building structures. A modified Coupled Two-Beam (CTB) model equipped with classical and non-classical damping has been proposed and solved analytically. In this system, complementary (non-classical) damping models composed of bending and shear mechanisms have been defined. A spatial shear damping model which is non-homogeneously distributed has been adopted in the CTB formulation and used to equivalently model passive dampers, viscous and viscoelastic devices, embedded in building systems. The application of continuum-based models for the dynamic analysis of shear wall systems has been further discussed. A reference example has been numerically analyzed to evaluate the efficiency of the presented CTB, and the optimization problems of the shear damping have been finally ascertained using local and global performance indices. The results reveal the superior performance of non-classical damping models against the classical damping. They show that the critical position of the first modal rotation in the CTB is reliable as the optimum placement of the shear damping. The results also prove the good efficiency of such a continuum model, in addition to its simplicity, for the fast estimation of dynamic responses and damping optimization issues in building systems.

Behaviour of recycled aggregate concrete beam-column connections in presence of PET fibers at the joint region

  • Marthong, Comingstarful
    • Computers and Concrete
    • /
    • v.21 no.6
    • /
    • pp.669-679
    • /
    • 2018
  • In this paper the behavior of reinforced concrete (RC) beam-column connections under cyclic loading was analyzed. The specimens, manufactured in a reduced-scale were made of (a) recycled aggregate concrete (RAC) by replacing 30% of natural coarse aggregate (NCA) with recycled coarse aggregate (RCA) and (b) RAC incorporating Polyethylene terephthalate (PET) fiber i.e., PET fiber-reinforced concrete (PFRC) at the joint region. PET fiber (aspect ratio=25) of 0.5% by weight of concrete used in the PFRC mix was obtained by hand cutting of post-consumer PET bottles. A reference specimen was also prepared using 100% of NCA and subjected to similar loading sequence. Comparing the results the structural behavior under cyclic loading of RAC specimens are quite similar to the reference specimens. Damage tolerance, load resisting capacity, stiffness degradation, ductility, and energy dissipation of the RAC specimens enhanced due to addition of PET fibers at the joint region. PFRC specimens also presented a lower damage indices and higher principal tensile stresses as compared to the RAC specimens. The results obtained gave experimental evidence on the feasibility of RAC for structural use. Using PET fibers as a discrete reinforcement is recommended for improving the seismic performance of RAC specimens.

Decentralized Control of Building Structures Installed with Semi-active MR Damper (준능동 MR 댐퍼가 설치된 건축 구조물의 분산제어)

  • Youn, Kyung-Jo;Lee, Sang-Hyun;Min, Kyung-Won;Lee, Sung-Kyung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2007.11a
    • /
    • pp.127-132
    • /
    • 2007
  • In this paper, to overcome local damages of structures, an uncertainty of structural model, installing sensors of structures, and economics of building system, decentralized semi-active magnetorheological(MR) damper using the displacement or velocity transferred to the response of floor installed damper is proposed. Relative magnitude between the control force of dampers and the story shear force is difined as design variables and the performance indices response spectra analysis through nonlinear time history analysis excited by seismic loads is performed according to this design variables. And the performance of this decentralized MR damper is compared with previous centralized LQR control algorithm using 3-stories benchmark building structure excited by El Centro (1940, N.S) in order to evaluate the application of building structures.

  • PDF

Vibration control of hysteretic base-isolated structures: an LMI approach

  • Pozo, Francesc;Pujol, Gisela;Acho, Leonardo
    • Smart Structures and Systems
    • /
    • v.17 no.2
    • /
    • pp.195-208
    • /
    • 2016
  • Seismic isolation systems are essentially designed to preserve structural safety, prevent occupants injury and properties damage. An active saturated LMI-based control design is proposed to attenuate seismic disturbances in base-isolated structures under saturation actuators. Using a mathematical model of an eight-storied building structure, an active control algorithm is designed. Performance evaluation of the controller is carried out in a simplified model version of a benchmark building system, which is recognized as a state-of-the-art model for numerical experiments of structures under seismic perturbations. Experimental results show that the proposed algorithm is robust with respect to model and seismic perturbations. Finally, the performance indices show that the proposed controller behaves satisfactorily and with a reasonable control effort.

Inelastic displacement-based design approach of R/C building structures in seismic regions

  • Rubinstein, Marcelo;Moller, Oscar;Giuliano, Alejandro
    • Structural Engineering and Mechanics
    • /
    • v.12 no.6
    • /
    • pp.573-594
    • /
    • 2001
  • A two-level displacement-based design procedure is developed. To obtain the displacement demands, elastic spectra for occasional earthquakes and inelastic spectra for rare earthquakes are used. Minimum global stiffness and strength to be supplied to the structure are based on specified maximum permissible drift limits and on the condition that the structure responds within the elastic range for occasional earthquakes. The performance of the structure may be assessed by an inelastic push-over analysis to the required displacement and the evaluation of damage indices. The approach is applied to the design of a five-story reinforced concrete coupled wall structure located in the most hazardous seismic region of Argentina. The inelastic dynamic response of the structure subjected to real and artificially generated acceleration time histories is also analyzed. Finally, advantages and limitations of the proposed procedure from the conceptual point of view and practical application are discussed.