جستجوی مقالات مرتبط با کلیدواژه « response » در نشریات گروه « فنی و مهندسی »
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Today, with the expansion of low-inertia (such as wind power plants) and non-inertia (such as photovoltaic power plants) technologies, the amount of network inertia and power related to the primary frequency response has decreased significantly. As a result, in the event of disturbances, the frequency changes with a relatively higher slope and it may violate its permissible range. To solve this problem, several methods have been presented so far that create artificial inertia by power electronic converters connected to storage devices or renewable generation. Therefore, the models make the operation of these sources similar to traditional power plants and increase their contribution to the frequency response during storage contribution events. In this paper, the sensitivity analysis of energy storage contribution to providing inertia for the primary frequency response has been carried out. IEEE 3-bus and 118-bus networks are used as test networks. MATLAB software is also adopted for optimization. The results show the impact of each storage parameter on the frequency response and how it is possible to meet the frequency response limitations of the network by managing the storage devices.Keywords: Primary Frequency, Response, Energy Storage, Virtual Inertia, Sensitivity Analysis}
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This paper deals with the application of discriminant analysis in an electrical discharge machining (EDM) process to determine the comparative contribution of each of its input parameters on the measured responses. It also identifies the most significant EDM process parameters influencing those responses. For this process, voltage, current, pulse-on time and pulse-off time are considered as the input parameters, whereas, material removal rate, electrode wear rate and surface roughness are the responses. Based on the past and simulated experimental data, both simultaneous and step-wise estimations are carried out for each of the three responses showing the relationships between the EDM process parameters and the considered responses. It is observed that in both these estimations, pulse-off time, current and pulse-on time respectively evolve out as the most significant parameters for material removal rate, electrode wear rate and surface roughness. Step-wise estimation identifies voltage as the least significant input parameter for all these responses. The developed discriminant functions, which can also help in predicting the responses, are finally cross-validated.Keywords: discriminant analysis, EDM process, Process parameter, Response}
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In this paper, the performance of photodetectors based on CH3NH3PbBr3 organic‐inorganic hybrid was evaluated, given their wide applications in different industries. This structure an appropriate for the active layer of photodetector device. Impressive results are concluded by changing the halogen atom and the energy gap of the hybrid structures. The obtained results reveal that the investigation of the appropriate organic cation and suitable halogen atom, as well as the concentration of the hybrids in the photodetectors, are necessary to find a suitable condition for an effective photodetectors. Exciting results are achieved by considering the Current-voltage (I-V) curves of darkness and light. The I-V curve with 1.8 wt. % concentration of CH3NH3PbBr3 organic‐inorganic hybrid shows the Isc of 1 μA and response of 0.027 μA/W. The device with 1.2 wt. % concentration showed Isc of 0.25 μA and response of 0.006 μA/W. Perovskites are optically configurable so that they acquire proper band gaps with high slope absorption edge and considerable efficiencies in collecting the charges produced by the light.
Keywords: Photodetector, Optoelectronic Device, Perovskite, Response} -
Many projects fail to achieve their expected benefit, cost, scope, and time objectives because their related risks and uncertainties reduce the accuracy in properly estimating the objectives and, thus, reduce the project efficiency. Since risks are accompanied with uncertainties and lack of reliability, many of them are irremovable in construction projects and their proper management is the only way to prevent damage. Hence, before a project starts, it is quite necessary that its risks should be identified, quantified, and evaluated to prevent them to occur using proper strategies and prioritization methods. As road construction projects involve numerous activities, and unexpected factors affect their final time and cost, the present study has identified their related risks by reviewing the literature and asking the experts’ opinions, prioritized them by the traditional Failure Mode and Effect Analysis (FMEA), selected the critical ones, and used the Monte Carlo simulation technique to quantitatively analyze their effects on the project time/cost scheduling. Also, sensitivity analysis was done by varying the percent occurrence probability of risks to evaluate determine the relationship between the percentage of probability of occurrence of risks and time and cost of road projects. Finally, responses to identified risk provided in order to reduce their effects on the time and cost of road construction projects.Keywords: Risk Analysis, Road Project, quantitative, qualitative, Response}
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Higher dimensional accuracy along with better surface finish of various advanced engineering materials has turned out to be the prime desideratum for the present day manufacturing industries. To achieve this, non-traditional machining (NTM) processes have become quite popular because of their ability to produce intricate shape geometries on diverse difficult-to-machine materials. To allow these processes to operate at their fullest capability, it is often recommended to set their different input parameters at the optimal levels. Thus, in this paper, a new technique combining grey correlation method and evaluation based on distance from average solution is applied for simultaneous optimization of three NTM processes, i.e. photochemical machining process, laser-assisted jet electrochemical machining process and abrasive water jet drilling process. The derived optimal parametric combinations outperform those as identified by the other popular multi-objective optimization techniques with respect to the considered response values. The results of analysis of variance also identify the most influencing parameters for the said NTM processes. Finally, the developed surface plots would help the process engineers in investigating the effects of different NTM process parameters on the corresponding grey appraisal scores.Keywords: Non-traditional machining process, Grey correlation, EDAS, optimization, Process parameter, Response}
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در این مقاله یک آشکارساز مبتنی بر پدیده شکست بهمنی (InGaAs/Si SACM APD) برای آشکار سازی در طول موج 1550 نانومتر ارایه گردیده است . این آشکارساز با ساختا ر ی ساده ، از حیث لایه ها تعریف و کمیت های اصلی آشکار سازی آن همانند جریان تاریک، جریان تابش، بهره و پاسخ دهی ،بهینه شده است. وجه برتری و تمایز این آشکار ساز این است که ولتاژ بایاس آن کوچکتر از مدل های موجود در مراجع معرفی شده می باشد و کمیت های آشکار سازی آن نیز، قابل رقابت با انها می باشد. این ولتاژ بایاس حداقل %41 از دیگر مراجع تطبیقی درشرایط مشابه کمتر است. در شاخص (0.9V_br) ، جریان تابش mu A 8.3 و جریان تاریک nA 4.9 حاصل گشته است. در ولتاژ بایاس 25 ولت جریان تابش mu A 51 و جریان تاریک nA 21 نسبت به فوتودیود مشابه افزایش می یابد. از این آشکار ساز برای کاربری های خاصی که نیاز به جریان تاریک بسیار پایین دارند نیز، می توان بهره برداری نمود.
کلید واژگان: آشکار ساز, فوتو دیود شکست بهمنی, پاسخ دهی, جریان تابش, جریان تاریک}In this paper, an avalanche photodiode (InGaAs/Si SACM APD) for detection at 1550 nm is presented. This detector has a simple structure, defined in terms of layers and its main detection parameters such as dark current, photocurrent current, gain and responsivity are optimized. The advantage and distinction of this detector is that its bias voltage is smaller than the models available in the references and its detection parameters can compete with them. This bias voltage is at least 41% lower than other adaptive references in similar conditions. In the index (0.9V_br), the photocurrent is8.3 u A and the dark current is 4.9 nA. At a bias voltage of 25 volts, the photocurrent and the dark current to 51 u A and 21 nA increase compared to the same photodiode. This detector can also be used for special applications that require very low dark current.
Keywords: Detector, Avalanche Photodiode, Response, Dark current, Photocurrent} -
Scientia Iranica, Volume:28 Issue: 6, Nov-Dec 2021, PP 3653 -3674Computer numerical control (CNC) is a manufacturing concept where machine tools are automated to perform some predefined functions based on the instructions fed to them. CNC turning processes have found wide ranging applications in modern day manufacturing industries due to their capabilities to produce low cost high quality parts/components with very close dimensional tolerances. In order to exploit the fullest potential of a CNC turning process, it should always be operated while setting its different input parameters at their optimal levels. In this paper, two classification tree algorithms, i.e. classification and regression tree (CART) and Chi-squared automatic interaction detection (CHAID) are applied to study the effects of various turning parameters on the responses and identify the best machining conditions for a CNC process. It is perceived that those settings almost match with the observations of the earlier researchers. The CART algorithm outperforms CHAID with respect to higher overall classification accuracy and lower prediction risk.Keywords: CNC turning process, Decision Tree, CART, CHAID, Parameter, Response}
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در طول سالیان اخیر کاربرد میراگرهای جرمی برای سازه های در برابر بارهای محیطی یا لرزه ای افزایش پیدا کرده است. یک گام مهم در طراحی و کاربرد میراگرهای جرمی، تخمین پارامترهای مودال است که همواره با مشکلاتی همراه بوده است. در این مقاله تلاش شده چارچوبی برای تخمین پارامترهای مودال میراگر جرمی؛ با ترکیب مدلهای آزمایشگاهی روی میز لرزه و تکنیک آنالیز مودال، به عنوان مثال روش تجزیه فرکانسی؛ ارایه شود. برای این منظور مطالعات آزمایشگاهی روی قاب پنج طبقه فولادی دارای میراگرهای جرمی با نسبت جرمی 01/0 و1/0 که در معرض تحریک دو زلزله مقیاس شده کوبه (Kobe) و ایمپریال ولی (Imperial valley) قرار گرفته اند، صورت گرفته است. همچنین پاسخهای سازه در حین زلزله با کمک سنسورهای که روی سازه نصب شده، ثبت شده و با کمک پاسخهای به دست آمده، مشخصات دینامیکی سازه دارای میراگر جرمی با کمک روش آنالیز مودال آزمایشگاهی (Operational Modal Analysis) تخمین زده می شود. در این مقاله از روش تجزیه فرکانسی (Frequency Domain Decomposition) برای تخمین پارامترهای دینامیکی میراگر استفاده شد. همچنین نسبت میرایی به دست آمده از روش تجزیه فرکانسی با مقادیر روش کلاسیک عددی مقایسه گردیده و مشاهده شد که روش مذکور توانایی مناسبی در برآورد پارامترهای دینامیکی میراگر دارد. این مقاله همچنان نشان میدهد که تحریک سازه آزمایشگاهی روی میز لرزه چنانچه همراه با تحلیل مودال آزمایشگاهی باشد، میتواند موفقیت زیادی در طراحی میراگرهای جرمی داشته باشد. همچنان محققان میتوانند با دقت بالایی پاسخهای سازه را در شرایط واقعی سازه و زلزله تخمین زده و در عین حال با صرف هزینه کم برای ساخت مدلهای آزمایشگاهی میراگر جرمی، میتوان پارامترهای بهینه میراگر جرمی را به دست آورد.
کلید واژگان: میراگر جرمی, پاسخ, فرکانس طبیعی, نسبت میرایی, تجزیه فرکانسی}Tuned mass dampers (TMDs) are being increasingly used for protection of structures against seismic and environmental loads. An important step in design and application of TMDs is the evaluation of TMD parameter which can cause be associated with serious difficulties. In this paper, we attempt to provide a framework to evaluate the modal parameters of TMDs using a combination of experimental test on shake table and a relatively recent modal analysis technique, namely Frequency Domain Decomposition (FDD). In order to achieve this, a series of test were conducted on a 5-storey steel frame was subjected to excitations from two scaled earthquakes (Imperial Valley and Kobe) ) while damped using two TMDs with mass ratios of 0.01 and 0.1.Mounted instrumentations recorded the structural response during the earthquakes and the recorded response was then used for an operational modal analysis (OMA) in order to estimate the dynamic characteristics of the TMDs. The FDD technique was used in this paper which was employed to estimate the parameters of TMDs. The damping ratios obtained from FDD method was compared with classical methods to verify its accuracy and capabilities in extraction of the modal parameters of TMDs. This paper shows that the use of shake table experiments coupled with the post-experiment modal analysis can be successfully used in TMD design and enables the researchers and practitioners to accurately estimate and test the response of the structures under relatively realistic conditions, which consequently allows low-cost testing of TMDs for optimum TMD selection.
Keywords: Tuned mass damper, Response, Natural frequency, Damping Ratio, Frequency Domain Decomposition} -
This study proposes a novel mathematical model for redesigning existing relief logistics network including suppliers, distribution centers and demand nodes along with integrating the measures in preparedness and response phases, simultaneously. In order to improve the accessibility and connectivity, certain precautionary measures for strengthening and rehabilitation of the links have been taken into account in the preparedness phase. In addition, a new debris clearance scheduling model for blocked links is modeled in accordance with the rehabilitation strategies. To overcome the uncertainty in a predefined destruction scenario tree, a multi-stage stochastic programming has been applied in a real case study. The results obtained in the proposed model indicate that the redesigned network leads to better performance in dealing with evacuees’ requested relief as compared to the results obtained by the existing network. Moreover, the results clearly demonstrate the significant value of solutions determined by multi-stage stochastic programming.Keywords: Relief logistics reconfiguration, preparedness, response, multi-stage stochastic programming, Rehabilitation, debris clearance scheduling model (DCSM), geographic information system (GIS)}
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The response spectrum of an oscillator with bilinear stiffness excited by band-limited Gaussian white noise is considered. The response is obtained by integrating over all energy levels weighting each with the stationary probability density of the energy. The procedure presented leads to estimates of linear and nonlinear response spectra in frequency domain and agrees well with those obtained by direct numerical simulation. Development of stochastic-based response spectra based on the frequency information concerning ground motions is important in engineering. Approximation of non-stationary ground motions by band-limited white noise is shown to be adequate for systems at the structural periods of engineering interest. Formulating the nonlinear response based on the excitation frequency information opens a door for wider use of seismological theory for regions with scarcely available recorded ground motion data. Despite simplicity and computational efficiency of the method, it provides an accurate prediction of the observed nonlinear response spectra on average.Keywords: Response, Bandlimited white noise, Bilinear, Energy balancing}
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با توجه به کاربرد وسیع پی های شمعی، ایمنی شمعها در زمان زلزله از اهمیت ویژه ای برخوردار است. تحقیقات نشان داده است که علاوه بر نیروی ناشی از روسازه، اثرات اندرکنش کینماتیکی خاک-شمع باعث اعمال تقاضای لرزه ای قابل توجهی به شمع ها در محیط های با خاک لایه ای می شود. در این مقاله از نرم افزار اجزاء محدود سه بعدی ABAQUS برای تحلیل لرزه ای اندرکنش کینماتیکی گروه شمع در خاک های لایه ای دارای رفتار غیرخطی استفاده شده است. پس از ارزیابی صحت نتایج روش تحلیل عددی تحت بارگذاری های استاتیکی و دینامیکی، اثرات اندرکنش کینماتیکی روی رفتار مکانیکی گروه شمع واقع در خاک دو لایه ای (لایه ی نرم بر روی لایه ی سخت) بحث و بررسی می گردد. مطالعات پارامتری شامل عوامل موثر بر پاسخ سیستم خاک-شمع نشان می دهد که نسبت فاصله به قطر شمع، تعداد شمعها درگروه، قطر شمع، نحوه ی اتصال شمع به کلاهک و تغییر مشخصات لایه های خاک، تاثیر قابل ملاحظه ای در رفتار گروه شمع در برابر زلزله دارد.
کلید واژگان: تحلیل غیرخطی, زلزله, گروه شمع, اندرکنش کینماتیکی, خاک لایه ای}During earthquakes, piles undergo stresses due both motion of the superstructure (i.e. inertial interaction) and that of the surrounding soil (i.e. kinematic interaction). In practice, structural engineers commonly take into account stresses induced by the inertial interaction, which is responsible for pile head failure, but they neglect the effects of the kinematic interaction that is responsible for failures along pile’s length in the case of layered soils with highly contrasting mechanical characteristics even in the absence of the superstructure. Thus, the evaluation of kinematic forces developing in piles during earthquakes has been receiving increased interest from the researchers. Numerical methods for the analysis of kinematic soil-pile interaction can be classified into two groups; continuum-based approaches and Winkler methods [1-3]. It has been customary in professional engineering and research practices to assume a linear behaviour for the soil and the pile foundation. However, under strong excitation, the nonlinear behaviour of soil media at the soil-pile interface has a strong influence on the response of the pile foundation. The aim of this study is to investigate the influence of soil nonlinearities on the kinematic interaction forces of pile groups embedded in layered soil deposits during seismic actions. Figure (1) shows the assumed soil-pile group case with 5 by 5 piles embedded in two layer subsoil profile. The pile has been considered as an elastic beam, while the soils have been modelled using the elastic-plastic solid element. The corresponding 3D finite element mesh has been shown in Figure (2). Based on the symmetry, only half of the model is meshed. Dynamic numerical analysis has been performed using the FE program ABAQUS [4]. Necessary parameters to simulate the examined cases are listed in Table (1). It is worth noticing that the comparison with availableexperimental and theoretical results in the literature has been made to validate the numerical model. The maximum displacements and the envelopes of kinematic bending moments and axial forces along the piles depth have been reported in Figure (3) due to the 1978 Tabas, Iran earthquake ground motion at the Dayhook station. As shown, it can be observed that the kinematic force distributions present relative maximum values very close to the layer interface. On the other hand, the diagram of the maximum displacements is characterized by a shape very similar to the first vibration mode of the soil deposit with maximum value at the piles head and almost zero value near the bedrock. In addition, the effects of kinematic group interaction lead to a decrease of bending moments at the pile head and also the layer interface as compared to the results from the single pile. Finally, the influence of main parameters governing the seismic response of piles like the space-diameter ratio, number of piles in the group, pile dimater, pile-to-cap fixity condition and the variation of soil layers properties are discussed.Keywords: Pile Group, Kinematic Interaction, Nonlinear Seismic, Response, Finite Element} -
Scientia Iranica, Volume:21 Issue: 6, 2014, PP 2399 -2418Modern societies are strongly dependent on the continuous and efficient operation of electric power systems as one of the critical infrastructures. Besides, information and communication systems play a crucial role in resiliency enhancement of the power system. As power communication systems are vulnerable against physical and cyber challenges, these systems can be an internal source of threats for power grids by themselves. Therefore, there is a need to identify and study the threats and weaknesses of power communication systems using a comprehensive framework. This framework helps power communication network planners evaluate all challenges and their numerous effects on the system, as a very important step in designing such systems. In the present paper, we propose such a framework by introducing the concept of ‘resiliency matrix’. In this regard, the resiliency of two alternative network plans, both of which are the solutions of a multi objective optimal design problem, is evaluated and compared using the proposed framework. The results reveal that the defined framework is capable to enhance network resiliency and thus can be used as a complementary step to design optimal and robust power communication networks.Keywords: Critical Infrastructure, Resiliency Metric, Resiliency Index, Resiliency Matrix, Power Communication System, Challenge, Response}
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در برآورد خطرپذیری لرزه یی سازه ها از سنجه های مختلف از شدت زلزله می توان سود جست که در این بین، طیف پاسخ شتاب ((S_a(T) شناخته شده ترین آنهاست. در سال های اخیر با تاکید بر «ناکامل» بودن این سنجه، تحقیقات دامنه داری صورت پذیرفته که ثمره ی آن ارائه ی روش هایی برای برآورد واقع گرایانه تر پاسخ سازه هاست. در این نوشتار، ضمن بازتعریف این مسئله به بررسی سیر پژوهش های سال های اخیر و دستاوردهای آن پرداخته شده است. یافته های سال های اخیر حاکی از آن است که به کارگیری طیف یکنواخت خطر (U H S) برای تحلیل سازه ها که در آیین نامه های امروزی استفاده می شود، منجر به برآورد محافظه کارانه ی پاسخ می شود. نقد روش فعلی آیین نامه ها برای انتخاب شتاب نگاشت های زلزله و نیز معرفی نسل نوینی از طیف پاسخ با عنوان طیف میانگین شرطی (C M S)بخش دیگری از این نوشتار است.
کلید واژگان: خطر, خطرپذیری, سنجه ی شدت, پاسخ, اریبی}From the various intensity measures that may be applied to evaluation of the seismic risk of structures, the acceleration response spectrum, Sa(T), is the most famous. As a key assumption in usual risk assessment procedures, such as PEER methodology, the structural response depends only upon the applied intensity measures, and not on any other properties of ground motion. This required condition is termed the ``sufficiency'' of the used intensity measure. The limited ``sufficiency'' of Sa(T) has been emphasized in recent research and, as a result, different methods have been proposed to modify structural response analysis. In this paper, the problem has been re-defined and then recent studies have been surveyed. The inelastic displacement response spectrum is another alternative for Sa(T). The intensity measure vector, as an innovative approach for bias reduction, has been also reviewed. This paper is mainly focused on the spectral shape concern. It has been discussed how the spectral shape of ground motion affects the structural nonlinear response. Epsilon, as a well known seismological parameter, is introduced as a convenient indicator of spectral shape. It has been shown that epsilon has significant effects on the nonlinear response of structures. As a convenient approach for reliable ground motion selection, the hazard related target epsilon is calculated first, and then the compatible ground motion is selected. A convenient procedure has been introduced in this paper, in order to find the target epsilon and eta values at different hazard levels. In the second half of this paper, the current code conformed approach for ground motion selection has been discussed. All seismic design codes and guidelines require scaling of a number of selected ground motions so that they match or exceed a target spectrum, i.e. uniform hazard spectrum (UHS). The recent findings show that application of the UHS for analysis of structures leads to a conservative estimation of structural response. Finally, a new generation of response spectrum, named the conditional mean spectrum (CMS), has been introduced. The CMS presents the expected response spectrum, conditioned on occurrence of a target spectral acceleration value at the period of interest. It has been shown that this is a more realistic target spectrum for ground motion selection in comparison with UHS.
Keywords: Hazard, Risk, Intensity Measure, Response, Bias, Selection} -
Near-fault ground motions with long-period pulses can place severe demands on structures near an active fault. These pulse-type ground motions can be represented by pulse sequences with simple shapes. Half-sinusoidal pulse sequences are used to approximate recorded ground motions and dynamic responses of SDOF system under the excitation of these pulse sequences are studied. Four cases are considered: (1) variation in duration of successor sub-pulse; (2) variation in duration of predecessor sub-pulse; (3) variation in amplitude of successor sub-pulse; and (4) variation in amplitude of predecessor sub-pulse. The corresponding acceleration, velocity and displacement response spectra of these pulse sequences are studied. The analysis on SDOF system shows that in some cases the responses are strongly affected by the changes of duration and/or amplitude of the sub-pulse. The study can be useful to understand the influences of sub-pulse in the near-fault pulse-type ground motions.
Keywords: near-fault, pulse sequences, sub-pulse, variations in duration, amplitude, response} -
در بررسی خواص دینامیکی تیرهای لانه زنبوری لازم است که شدت تحریک مود دینامیکی این تیرها در ازای بارگذاری های مختلف مورد بررسی قرار گیرد. واضح است که در ازای بارگذاری خاص کلیه مودهای یک سازه تحریک نشده و واکنش سازه به خواص بارگذاری، بستگی کامل دارد. در مقاله حاضر با استفاده از روش المان های محدود (نرم افزار ANSYS) یک بار دینامیکی با خواص نویز سفید در یک باند فرکانسی مناسب روی تیرهای طره لانه زنبوری و پروفیل های معمولی اعمال و خصوصیات دینامیکی و مودهای مختلف تحریک شده آنها مورد بررسی و مقایسه قرار گرفته اند. ملاحظه می شود که برای تحریک و شنامعمولی اعمال و خصوصیات دینامیکی و مودهای مختلف تحریک شده آنها مورد بررسی و مقایسه قرار گرفته اند. ملاحظه می شود که برای تحریک و شناسایی خواص دینامیکی این تیرها نوع بارگذاری کاملا مهم می باشد. در تیر طره با بارهای گسترده یکنواخت با خواص نویز سفید صرفا بعضی از مودهای ارتعاشی یعنی مودهای خمشی تحریک شده و اثر بعضی از مودهای دیگر از جمله مودهای پیچشی حذف می گ مهم می باشد. در تیر طره با بارهای گسترده یکنواخت با خواص نویز سفید صرفا بعضی از مودهای ارتعاشی یعنی مودهای خمشی تحریک شده و اثر بعضی از مودهای دیگر از جمله مودهای پیچشی حذف می گردد. لذا برای تحریک کلیه مودها بایستی بارگذاری هایی با باند مناسب فرکانسی اعمال می شود ک بتواند کلیه مودهای ارتعاشی تیر تحریک نماید. همچنین قابل ذکر است که روش جاری مبین ضعیفتر بودن تیرهای لانه زنبوری در مقایسه با تیرهای معمولی در ازای بارهای ثقلی دینامیکی است، که این بارها مولد لنگرهای خمشی و تحریک مودهای خمشی می گردد.کلید واژگان: تیره طره, لانه زنبوری, مودهای خمشی, المانهای محدود, طیف پاسخ, نویز سفید}In investigation of dynamic specifications of castellated beams, it is necessary to be studied the excitation intensity of dynamic mode shapes for different loading conditions. It is evident that for a specific loading, not all modes of a structure are excited and the structural response depends on the applied loading specifications. In this paper using the finite element method (based on ANSYS software), a dynamic load with properties of white noise in a proper frequency range is applied on the both cantilever catellated and plain webbed beams. The dynamic specifications and different excited modes of them are taken into investigation. It could be seen that the loading conditions are very important in order to excite and define the dynamic specifications of these beams. In a uniformly loaded cantilever beam with the white-noise properties, merely some of the vibration modes, that is, the flexural modes are excited and the effects of some of the other modes such as torsional modes are eliminated. Therefore, in order to excite all of the vibration modes a loading with proper frequency band should be applied. Also it should be mentioned that the current method indicates that castellated beams are weak in comparison with plain webbed beams subjected to dynamic gravity loads which cause bending moments and excite the flexural modes.Keywords: Cantilever, Castellated, Bending Mode, Finite element, Response, White-Noise}
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