DAMPING: A SENSITIVE STRUCTURAL PROPERTY FOR DAMAGE DETECTION
Data from vibration measurements opens a way to damage assessment by correlatingchanges in system dynamic parameters with damage indicators. Most methods proposed in theliterature are based on the measurement of natural frequencies or modal shapes and modelling damageas local reduction in structural stiffness. In some particular applications these methods, however, haveseveral practical limitations on account of their low sensitivity to damage. This paper shows thatdamping can be used as a damage-sensitive system property and presents a procedure forinstantaneous natural frequencies and damping identification from free vibration response using thewavelet transform. Experimental and simulated examples show that in the structures analyzed damagecauses important variations of damping…
Application of a robust vibration-based non-destructive method for detection of fatigue cracks in structures
This paper presents the application of a novel vibration-based technique for detecting fatiguecracks in structures. The method utilizes the empirical mode decomposition method (EMD) toestablish an effective energy-based damage index. To investigate the feasibility of the method,fatigue cracks of different sizes were introduced in an aluminum beam subjected to a cyclic loadunder a three-point bending configuration. The vibration signals corresponding to the healthyand the damaged states of the beam were acquired via piezoceramic sensors. The signals werethen processed by the proposed methodology to obtain the damage indices. In addition, for thesake of comparison, the frequency and damping analysis were performed on the test specimen.The results of this study concluded with two major…
Review of Vibration-Based Damage Detection and Condition Assessment of Bridge Structures using Structural Health Monitoring
As a part of vital infrastructure and transportation networks, bridge structures must function safely at alltimes. However, due to heavier and faster moving vehicular loads and function adjustment, such asBusway accommodation, many bridges are now operating at an overload beyond their design capacity.Additionally, the huge renovation and replacement costs always make the infrastructure ownersdifficult to undertake. Structural health monitoring (SHM) is set to assess condition and foreseeprobable failures of designated bridge(s), so as to monitor the structural health of the bridges. TheSHM systems proposed recently are incorporated with Vibration-Based Damage Detection (VBDD)techniques, Statistical Methods and Signal processing techniques and have been regarded as efficientand economical…
Review of Vibration-Based Damage Detection and Condition Assessment of Bridge Structures using Structural Health Monitoring
As a part of vital infrastructure and transportation networks, bridge structures must function safely at alltimes. However, due to heavier and faster moving vehicular loads and function adjustment, such asBusway accommodation, many bridges are now operating at an overload beyond their design capacity.Additionally, the huge renovation and replacement costs always make the infrastructure ownersdifficult to undertake. Structural health monitoring (SHM) is set to assess condition and foreseeprobable failures of designated bridge(s), so as to monitor the structural health of the bridges. TheSHM systems proposed recently are incorporated with Vibration-Based Damage Detection (VBDD)techniques, Statistical Methods and Signal processing techniques and have been regarded as efficientand economical…
Review of Vibration-Based Damage Detection and Condition Assessment of Bridge Structures using Structural Health Monitoring
As a part of vital infrastructure and transportation networks, bridge structures must function safely at alltimes. However, due to heavier and faster moving vehicular loads and function adjustment, such asBusway accommodation, many bridges are now operating at an overload beyond their design capacity.Additionally, the huge renovation and replacement costs always make the infrastructure ownersdifficult to undertake. Structural health monitoring (SHM) is set to assess condition and foreseeprobable failures of designated bridge(s), so as to monitor the structural health of the bridges. TheSHM systems proposed recently are incorporated with Vibration-Based Damage Detection (VBDD)techniques, Statistical Methods and Signal processing techniques and have been regarded as efficientand economical…
کاربرد میکروارگانیزم‌ها در تهیه مواد لبنی
عنوان پایان نامه: کاربرد میکروارگانیزم‌ها در تهیه مواد لبنیفرمت فایل: word
تعداد صفحات: ۱۰۱
شرح مختصر:
شیرامولوسیون پیچیده‌ای از پروتئین، چربی، قند و مواد معدنی است. شیرگاو تقریباً ۸۷% آب، ۵/۳% پروتئین، ۵/۳% چربی و ۵% لاکتوز دارد که البته در صد آب و چربی از شیر یک گاو به شیر گاو دیگر متفاوت است. محصولات بدست آمده از تخمیر شیر، مزه‌های متفاوتی دارند و به علت داشتن آب کمتر نسبت به شیر، مقاومتشان در برابر عوامل فساد غذایی بیشتر است. تخمیر شیر در…
برنامه محاسبه مشخصات کلوتوئید
در‌این‌برنامه‌اطلاعات مورد نیاز ترسم پلان مسیر ، بر اساس مختصات سومه های مسیر محاسبه خواهد شد . در ادامه نمونه خروجی این برنامه همراه با پلان مسیر آماده شده ، بر اساس این اطلاعات را می توانید دریافت کنید.
جهت دریافت نمونه خروجی برنامه کلیک کنید…
خواص ماهی و میگو و اثرات امگا ۳
عنوان تحقیق: خواص ماهی و میگو و اثرات امگا ۳ فرمت فایل: word
تعداد صفحات: ۶۳
شرح مختصر:
بشر از دیرباز از ماهی به عنوان یک ماده غذایی استفاده کرده است. تصاویر و اشکال در غارها و دیواره‌های معابر محل زندگی نشان دهنده قدمت چند هزار ساله استفاده از آن است، بشر حتی به صورت خام نیز آن را تجربه کرده است، البته پس از پختن به طعم بهتر آن پی برده و از آن پس در برنامه غذایی خود به عنوان یک غذای خوشمزه به طور مکرر استفاده کرده است.
البته طبیعی است که در…
Real-time structural damage detection using wireless sensing and monitoring system
Abstract. A wireless sensing system is designed for application to structural monitoring and damagedetection applications. Embedded in the wireless monitoring module is a two-tier prediction model, the autoregressive(AR) and the autoregressive model with exogenous inputs (ARX), used to obtain damage sensitivefeatures of a structure. To validate the performance of the proposed wireless monitoring and damage detectionsystem, two near full scale single-story RC-frames, with and without brick wall system, are instrumented withthe wireless monitoring system for real time damage detection during shaking table tests. White noise andseismic ground motion records are applied to the base of the structure using a shaking table. Patternclassification methods are then adopted to classify the structure…
Dynamic changes resulting from a variety of causes (e.g. structural damage or nonlinearity onset) may disturb or threaten the normal working condition
Dynamic changes resulting from a variety of causes (e.g. structural damage or nonlinearity onset) may disturb or threaten the normal working conditions of a system. The capacity to estimate the mechanical health condition of a structure using remote non-destructive techniques constitutes a substantial plan which allows to reduce maintenance costs and to ensure safety. Hence, questions such as the detection of those events have attracted the attention of countless researchers in recent times…