Frame Of Model Research Articles

Finite element analysis-based blast and seismic performance evaluation for RC frame with retrofitted ENTA damper systems

Blast loading and seismic excitations are widely recognized as the most detrimental occurrences that a building structure may encounter throughout its lifespan. Therefore, this study investigated the retrofitting capacity of external devices (ENTA damper systems) for reinforced concrete (RC) frames in term of enhancing their resistance under the combined effects of blast and seismic loads. This study presents the establishment of finite element (FE) models for retrofitted RC frames with ENTA damper systems through the utilization of the dynamic analysis software LS-DYNA. The investigation involved the validation for blast performance of RC column in order to identify the most effective method for modeling blasts. Additionally, the study aimed to validate the performance of RC frame models through effects of ENTA damper systems under seismic loading. Subsequently, a performance evaluation of RC frame structures was carried out to examine the impact of the ENTA damper systems when subjected to blast loading. The findings of the study indicate that the use of external ENTA damper systems effectively enhanced the rigidity and structural integrity of RC frames, while maintaining their ability to resist deformation. Finally, the damage assessment of blast and seismic performance is investigated based on various parameters such as ductility, drift and energy-based damage limits.

Полихудожественное взаимодействие обучающихся во время построения лингвокультурных сценариев как средство обогащения тематического словарного запаса студентов – будущих переводчиков (на примере английского языка)

The purpose of the study is to determine the influence of poly-artistic methodological support for the study of linguistic and cultural scenarios on the formation of lexical and grammatical foreign language skills among students at the Faculty of Translation. The initial understanding of the cognitive approach to teaching foreign languages in a narrow sense (only as a system-theoretical support for processes) led to its underestimation and oblivion. The article examines the current trends towards borrowing individual components of the cognitive approach for the development of a communicative method of learning foreign languages. The scientific novelty of the research consists in the introduction of a poly-artistic approach in the training of students – future translators through the adaptation of professional highly specialized exercises for the training of future actors, directors and theater critics for their subsequent integration into the process of studying English-language frame models and scenarios, which had not previously become the object of research. The relevance of the study lies in the fact that, despite many years of experience using a communicative approach in teaching foreign languages, many students still face difficulties activating passive thematic vocabulary and grammatical rules and, as a result, a language barrier. As a result of the study, it was found that in conditions of meaningful operation of language and speech skills, students present the educational process not as a set of rules or a set of information, but as a toolkit for independent creative language activity. Using the Kolmogorov-Smirnov λ-criterion and the Fisher φ*-criterion (circular transformation), the beneficial effect of artistic and methodological support for the construction of linguistic and cultural scenarios on the expansion of the thematic vocabulary of students within the framework of the theme “At the Restaurant” has been experimentally confirmed.

Pelatihan dan Sosialisasi Penggunaan Aplikasi Perhitungan Struktur Gedung (SAP2000)

The advancement of modern civil engineering, software designed to facilitate and expedite the structural analysis calculation process, especially for seismic analysis, is also becoming increasingly sophisticated. The presence of this software greatly facilitates civil engineers in conducting analyses. Conducting seismic analysis for tall buildings using hand calculations not only consumes a significant amount of time and effort but also increases the risk of calculation errors due to human error. Training and Socialization on the Use of Building Structure Calculation Applications (SAP2000) were conducted offline in the Computer Laboratory Room of the MRK Civil Engineering Department, Faculty of Engineering, Syiah Kuala University. In general, the training and socialization materials on the use of building structure calculation applications, included an Introduction to Application Features, Modeling Steps, Continuous Beam Modeling Tutorial, 2D Frame Modeling Tutorial, and 3D Frame Modeling Tutorial. Based on the monitoring during the training, the participants showed great enthusiasm. They highly appreciated this activity as it provided them with the opportunity to learn about building structure calculations, and there were requests for further training sessions. After the completion of the activity, the participants were asked to fill out a questionnaire regarding the effects of using the application. One of the questions asked was about the participants' understanding after the training, where 100% of the participants reported an improvement in understanding due to the training activities.

Wooden Spatial Structures Assembled with Disassembly Possible Simple Joints

The authors propose a new clamped joint system that can easily join wooden members together and a wooden spatial structure that utilizes this system. The proposed system can clamp wood members without the need for special joint machining. Two types of clamps have been developed: orthogonal clamps and rotational clamps. A frame system is developed using this joint system, which is a hemispherical dome with a diameter of 5.4 m and its membrane is tensioned using struts. A preliminary framework structural analysis and membrane stress analysis are conducted to confirm the safety of the frame. Full-scale mock-up was constructed to validate the frame model analysis and verify construction procedures. As a combinable structure, a small-scale spatial structure assembled using orthogonal clamps is also described. It is the cube-shaped structure 2.8 m wide consisting of wall and ceiling planes. Single clamp loading tests are conducted to understand the load-deformation relationship of the proposed clamped joint system and full-scale horizontal loading tests have been conducted.

Numerical Simulation on Aftershock Fragility of Low-Ductility RC Frames under Different Mainshock-Induced Damage Conditions

Aftershocks typically occur multiple times following major earthquakes, potentially inflicting enhanced damage. It is crucial to quantify the impact of aftershocks on the seismic performance of low-ductility reinforced concrete (RC) frames with different mainshock-induced damage states. For this purpose, this study investigated the aftershock fragility of low-ductility RC frames with different damage states induced by mainshocks via the case study of a six-story RC frame without a seismic design. The models of the low-ductility RC frames with different damage states were established via OpenSees software 2.5.0. Incremental dynamic analysis (IDA) was carried out to establish damage states induced by a mainshock. Then sixty-five real aftershocks were inputted to analyze the structures with different main-induced damage states. Aftershock fragility curves of low-ductility RC frame structures with different damage states were obtained. The results show that the exceedance probability of the low-ductility RC frame with mainshock-induced damage is higher than that of the intact low-ductility structure, corresponding to each limit state. The severity of the mainshock-induced damage directly amplifies the demand for a low-ductility RC frame in the subsequent aftershocks. As the mainshock-induced damage increases, the exceedance probability of the low-ductility RC frame undergoing more severe damage under aftershocks significantly increases.

Seismic responses and loss evaluation of RC frame with slotted infill walls

Infill walls are a primary source of structural loss under service level and design basis earthquakes, so developing high-performance infill wall is an effective strategy to reduce seismic loss. While several high-performance infill walls have been proposed, most studies only reveal the damage characteristics of infill walls at the component level. However, the interaction between infill walls and structures can alter the seismic response of structures and consequently affect the loss of infill walls under earthquakes. Therefore, it is necessary to investigate the seismic responses and loss of high-performance infill wall at the structural level. In this paper, the working mechanism and damage characteristics of the slotted infill wall (SIW) are firstly introduced and verified through cyclic loading test. Then, an in-plane hysteresis model of SIW is developed, and the calculation method of key parameters is proposed. Finally, a numerical analysis model of a 10-story frame with slotted infill wall (SIW-F) is developed to study the seismic response and seismic losses. The results indicate that SIW-F’s displacement response is larger than that of the frame with ordinary infill wall (OIW-F) on most floors. However, the floor acceleration response is less. The seismic loss of SIW-F is less than that of OIW-F, particularly under design basis earthquakes. The repair cost ratio of infill wall decreases from 19% to 8%, the total repair cost of the SIW-F decreases by 41%, and the total repair time also reduces by 25%.

Effective Video Summarization by Extracting Parameter-Free Motion Attention

Video summarization remains a challenging task despite increasing research efforts. Traditional methods focus solely on long-range temporal modeling of video frames, overlooking important local motion information that cannot be captured by frame-level video representations. In this article, we propose the Parameter-free Motion Attention Module (PMAM) to exploit the crucial motion clues potentially contained in adjacent video frames, using a multi-head attention architecture. The PMAM requires no additional training for model parameters, leading to an efficient and effective understanding of video dynamics. Moreover, we introduce the Multi-feature Motion Attention Network (MMAN), integrating the PMAM with local and global multi-head attention based on object-centric and scene-centric video representations. The synergistic combination of local motion information, extracted by the proposed PMAM, with long-range interactions modeled by the local and global multi-head attention mechanism, can significantly enhance the performance of video summarization. Extensive experimental results on the benchmark datasets, SumMe and TVSum, demonstrate that the proposed MMAN outperforms other state-of-the-art methods, resulting in remarkable performance gains.

On the impact of true polar wander on heat flux patterns at the core–mantle boundary

Abstract. The heat flux across the core–mantle boundary (CMB) is a fundamental variable for Earth evolution and internal dynamics. Seismic tomography provides access to seismic heterogeneities in the lower mantle, which can be related to present-day thermal heterogeneities. Alternatively, mantle convection models can be used to either infer past CMB heat flux or to produce statistically realistic CMB heat flux patterns in self-consistent models. Mantle dynamics modifies the inertia tensor of the Earth, which implies a rotation of the Earth with respect to its spin axis, a phenomenon called true polar wander (TPW). This rotation must be taken into account to link the dynamics of the mantle to the dynamics of the core. In this study, we explore the impact of TPW on the CMB heat flux over long timescales (∼1 Gyr) using two recently published mantle convection models: one model driven by a plate reconstruction and a second that self-consistently produces a plate-like behaviour. We compute the geoid in both models to correct for TPW. In the plate-driven model, we compute a total geoid and a geoid in which lateral variations of viscosity and density are suppressed above 350 km depth. An alternative to TPW correction is used for the plate-driven model by simply repositioning the model in the original paleomagnetic reference frame of the plate reconstruction. The average TPW rates range between 0.4 and 1.8° Myr−1, but peaks up to 10° Myr−1 are observed. We find that in the plate-driven mantle convection model used in this study, the maximum inertia axis produced by the model does not show a long-term consistency with the position of the magnetic dipole inferred from paleomagnetism. TPW plays an important role in redistributing the CMB heat flux, notably at short timescales (≤10 Myr). Those rapid variations modify the latitudinal distribution of the CMB heat flux, which is known to affect the stability of the magnetic dipole in geodynamo simulations. A principal component analysis (PCA) is computed to obtain the dominant CMB heat flux pattern in the different cases. These heat flux patterns are representative of the mantle convection cases studied here and can be used as boundary conditions for geodynamo models.

Cost-effective topology optimization of masonry structure reinforcements by a linear static analysis-based GA framework

The paper presents a novel optimization framework aimed at the minimization of seismic retrofitting-related costs for existing unreinforced masonry building structures. The framework provides topology optimization of reinforcements (reinforced plasters) to implement in masonry walls for the accomplishment of seismic safety checks under the reference seismic load combinations. Optimization is carried out by a genetic algorithm (GA) developed in MATLAB®, which controls a 3D finite element equivalent frame model of the masonry structure developed in OpenSees. The GA routine iterates the reinforcement configurations employing specific genetic operators. The feasibility of each candidate retrofitting solution is assessed by performing in-plane shear and flexural safety checks of masonry walls. The framework is finally tested with a case study masonry structure supposed to be made of average-quality or poor-quality masonry. Results will show that the proposed framework can effectively provide the minimization of seismic retrofitting costs for existing masonry structures, giving as output the optimal configuration of the reinforcements within the structural layout.

Analisis Framing Pemberitaan Relokasi Pulau Rempang pada Media Online kompas.com dan detik.com

This research was carried out using Robert Entman's framing model analysis on the online media kompas.com and detik.com. This research discusses the relocation of Rempang Island in the period September-November 2023. This research uses a qualitative approach. The object of this research is the Relocation of Rempang Island, which is a Government project, namely the development of the area that will become Rempang Eco City. The relocation of Rempang Island which is on Batam Island, Riau Islands, is a government project which has long been planned to build Rempang Eco City but only in 2023 will this development get investors so that this development can be realized, as a result of this the government has to carry out the relocation to the residents of Rempang, as a result of this there were demonstrations and clashes demanding that they not be relocated, demanding rights and clarity regarding this relocation issue from the government. The results of the research focus more on the meaning and prominence of messages in several news frames on kompas.com and detik.com.

Utilizing data-driven algorithms for blind modal parameter identification of structures from output-only video measurements

In structural dynamics and vibration analysis, modal identification plays a pivotal role in understanding and characterizing the dynamic behavior of complex systems. Traditional modal analysis techniques heavily rely on accurate sensor placement and knowledge of the excitation forces, which may not always be feasible or practical in real-world scenarios. Recently, non-contact video-based modal analysis methods for structures with arbitrary complexity using computer vision techniques have gained much importance. But these methods need to know ahead of time where the structure's natural frequency ranges are, and they use steerable pyramids, which are complicated multi-scale image decomposition filters. To address these issues, a blind modal identification technique is suggested to extract the modal parameters (modal frequency and mode shapes) from the recorded structural vibration video signal. The proposed algorithm for unsupervised machine learning is the Non-Negative Matrix Factorization (NNMF) method, which is combined with the Generalized Complexity Pursuit (GCP) method for blind source separation. The NNMF algorithm is directly applied to the raw pixel-time series made from the video data to get the temporal components, which are then separated using GCP to find the individual modal frequencies and mode shapes. The above algorithm is first validated on a numerical model and then implemented on laboratory scale models (cantilever, single-degree, and multi-degree frame models). Finally, the proposed methodology is implemented on real-world recorded structural vibration videos to determine its noise sensitivity, such as the Tacoma Narrows bridge and the London Millennium footbridge. The modal parameters extracted are compared with those from the available literature for validation. The estimation errors obtained from all the validations are well below 1%, which makes the technique quite suitable and reliable for structural vibration monitoring by identifying and reproducing complex vibration modes.

Study on Ring Deformation and Contact Characteristics of Thin-Walled Bearing for RV Reducer

The thin-walled rings of the RV reducer main bearings are prone to structural elastic deformation, which can significantly change the bearing mechanical characteristics. According to the actual assembly state of the RV reducer, the simulation model of the planetary frame–main bearings–pin gear housing is established considering the ring deformation. The model was used to calculate and comparatively analyze the ring deformation and contact characteristics of thin-walled bearings under rigid and flexible conditions, on the basis of which the mechanism of ring deformation was described, and the effects of load conditions, ring thickness and radial clearance on ring deformation, flexible contact characteristics, and ultimate carrying capacity were analyzed. The results show that the distribution of contact loads is the main factor affecting the ring deformation. The ring deformation can optimize the bearing contact characteristics, and the greater the deformation, the more pronounced the optimization effect. However, excessive ring deformation makes the contact ellipse more susceptible to truncation, which, in turn, reduces the ultimate carrying capacity. This study indicates a 38.2% decrease in the carrying capacity of the flexible ring model compared to that of the rigid ring model. In this paper, the effect of ring deformation on bearing mechanical characteristics is deeply discussed. The research results have important guiding significance for the structural optimization design of thin-walled bearings.

Effects of design and fabrication of segmented ship models on test results of wave-induced loads

The design and fabrication of segmented ship models have great effects on wave-induced loads in wave basins. Three different segmented ship models of a 20,000 TEU (twenty-feet equivalent unit) ultra-large container ship are designed and fabricated with different support frames and backbones. The shell and wooden frames of Models A and B were fabricated with the same method, however, the type of backbone and scale are different. Model C is a steel framing model, the dimensions of the frame members are validated by finite element method and the frame members are connected with welding technique. Suitable parameters are selected to design and fabricate Model C with the improved fabrication method. The calculated mode results of Model C are compared with the experimental data to validate the reasonability and advantage of the improved design and fabrication method. The dry and wet modes of the three ship models are measured and compared. The three different ship models are tested under typical conditions in different wave basins, and the corresponding test results are compared to reveal the effects of the fabrication method on structural elastic modes and wave-induced loads. Finally, the uncertainty analysis of the three model tests under typical conditions are conducted.

SEMANTIC CONTENT OF CONCEPT HELP CATEGORIZED AS PROPERTY IN CONTEMPORARY ENGLISH

The article raises the issue of conceptual-semantic analysis of units of different lexical-grammatical classes to indicate rivalry. The referent of objective reality represented by the RIVALRY concept is a certain situation as a set of its interdependent elements. The analysis of the semantic structure of nominative units contributes to the establishment of deep patterns of interaction between the structures of human consciousness and linguistic forms. Nominative possibilities of the linguistic picture of the world are implemented by lexical units that are subject to conceptual analysis to achieve the goal of linguistic-cognitive research - reconstruction of the content of the concept. Dictionary definitions of words of different lexical-grammatical classes to indicate rivalry contain generic and specific semes as lexical units that implement the corresponding cognitive characteristics and are called slot terminals. The frame acts as a classifier of lexical units in which the components of the reference situation of rivalry are actualized. The semantic-cognitive analysis of lexemes that form the primary and secondary synonymous series and most adequately reflect the studied conceptual category precedes the modeling of the prototypical informative structure of the concept of rivalry in terms of frame semantics. Slot ACTION, which captures information about the actions of direct participants, is represented by units of the lexical-grammatical category to indicate the rivalry process. The studied slots reflect knowledge about the causal, instrumental, location and time components of the frame model. The studied slots are correlated with a group of cognitive features that represent knowledge about the characteristics of actions.Thus, the causal set activates data on the reasons for entering into a rival interaction, options for ending it. The instrumental set accumulates information about the nature of the action, tactics, strategic goal; the quantity and quality of the means of action, about the quantitative and qualitative aspects of the goal, its varieties. The location and time of the frame captures knowledge about the type of the place and spheres of action, the duration of the rivalry and the time of its implementation.

Characterization of rotary valve control vibration system for vibration stress relief applications

To enhance the vibration system characteristic distortion and pressure loss, we propose a novel rotary valve control vibration system. The paper presents the designed structural composition and generation mechanism of the rotary valve control vibration system. It also derives the mathematical model for the rotary valve distribution process and the overall system. The flow field inside the rotary valve is dynamically simulated using the multiple reference frame model, allowing for the determination of the change rule of the rotary valve’s output characteristics. An AMESim model was developed to analyze the vibration characteristics of the rotary valve control system. The effects of parameters such as inlet pressure, motor speed, and oil supply pump displacement were investigated. A rotary valve control vibration system experimental bench was constructed to experimentally verify the output characteristics of the rotary valve and the vibration characteristics of the system. The results indicate that the characteristic curve of the designed vibration system closely resembles a sinusoidal wave. Additionally, the rotary valve exhibits low pressure loss, making it more suitable for vibration stress relief applications. By appropriately increasing the inlet pressure and decreasing the motor speed, the vibration characteristics of the system can be improved.

Lightweight Design of Heavy-duty Logistics Robot Based on ANSYS

Based on ANSYS Workbench, this paper carries out static analysis on the three-dimensional model of the heavy-duty logistics robot frame established by CAD software, obtains the displacement and stress distribution of the frame, adopts the variable density method and the level set method to carry out topological optimization analysis of the frame, and makes structural improvement on the frame according to the optimization results. The static analysis of the improved model is carried out by applying the same load and fixed constraints as the original model. The results show that the weight of the improved model is 45% lower than that of the original model when the stiffness of the material is satisfied, and the lightweight of the heavy-duty logistics robot frame is realized.

Heat transfer in a vessel-tubes array with a rotating baffle: A rotating frame modeling approach

Conveying heat from one medium to another is more critical when merging these media is banned. Thus, the media should flow individually in separate pipes. This paper explores the exchange of heat between tube bundles enclosed in a circular vessel with a rotating frame. The rotating frame serves to modulate the natural convection to mixed convection. The hot and cold tubes are distributed peripherally while the rotor is centered in the insulated vessel. The study focused on the configuration of the tubes, namely their number, size (r*), and radial position (e*), and how these parameters act with various Rayleigh numbers (Ra = 103 - 105) and rotational speeds (ω* = 0 - 400). The time-dependent equations are discretized and solved using the finite element method with rotating meshes. The outcomes indicate that the augmentation of Nusselt number with the rotational speed and Rayleigh number relies significantly on the radial position, the size as well as the number of hot tubes. The Nusselt number increases by 74.59 % and 9.57 % for Ra = 105 and 103, respectively, when the rotational speed is elevated from 0 to 200, whereas it increases by 308 % when the tube size is reduced from r* = 0.05 to r* = 0.01 at ω* = 200. It is deduced that the size of the tube is the supreme parameter affecting the Nusselt number.

Current Controller Design of Grid-Connected Inverter with Incomplete Observation Considering L-/LC-Type Grid Impedance

This paper presents a current control design for stabilizing an inductive-capacitive-inductive (LCL)-filtered grid-connected inverter (GCI) system under uncertain grid impedance and distorted grid environment. To deal with the negative impact of grid impedance, LC-type grid impedance is considered in both the system model derivation and controller design process of an LCL-filtered GCI system. In addition, the integral and resonant control terms are also augmented into the system model in the synchronous reference frame to guarantee the reference tracking of zero steady-state error and good harmonic disturbance compensation of the grid-injected currents from GCI. By considering the effect of grid impedance on the control design process, an incomplete state feedback controller will be designed based on the linear-quadratic regulator (LQR) without damaging the asymptotic stabilization and robustness of the GCI system under uncertain grid impedance. By means of the closed-loop pole map evaluation, the asymptotic stability, robustness, and resonance-damping capability of the proposed current control scheme are confirmed even when all the system states are not available. In order to reduce the number of required sensors for the realization of the controller, a discrete-time current-type full-state observer is employed in this paper to estimate the system state variables with high precision. The feasibility and effectiveness of the proposed control scheme are demonstrated by the PSIM simulations and experiments by using a three-phase GCI prototype system under adverse grid conditions. The comprehensive evaluation results show that the designed control scheme maintains the stability and robustness of the LCL-filtered GCI when connecting to unexpected grids, such as harmonic distortion and L-type and LC-type grid impedances. As a result, the proposed control scheme successfully stabilizes the entire GCI system with high-quality grid-injected currents even when the GCI faces severe grid distortions and an extra grid dynamic caused by the L-type or LC-type grid impedance. Furthermore, low-order distortion harmonics come from the background grid voltages and are maintained as acceptable limits according to the IEEE Std. 1547-2003. Comparative test result with the conventional one also confirms the effectiveness of the proposed control scheme under LC-type grid impedance thanks to the consideration of LC grid impedance in the design process.

An inelastic beam-like model for nonlinear dynamic analyses of multi-storey buildings

This paper presents an equivalent non-uniform inelastic beam-like model for the evaluation of the nonlinear behaviour of multi-storey buildings subjected to earthquake loadings. The proposed beam can be used to model buildings with non-uniform mass and stiffness distribution. The model is characterised by a number of degrees of freedom corresponding to the number of floors of the building and is conceived to predict its nonlinear dynamic response after a proper calibration based on the results of pushover analyses performed on a nonlinear FEM model. In spite of its simplicity, the proposed equivalent model provides, with a very low computational effort, an accurate representation of the nonlinear dynamic behaviour of the building comparable to that obtained through the more demanding nonlinear 3D FEM models. The effectiveness of the proposed simplified modelling approach is here validated by means of nonlinear dynamic analyses firstly performed on a benchmark known in the literature as SAC9 building, modelled as a plane steel frame structure and secondly on a three-dimensional reinforced concrete structure, designed according to old standard structural design rules. The very good agreement with the results obtained through accurate 3D FEM frame modelling, for different earthquake loadings, on the considered benchmarks provides a first validation of the proposed inelastic equivalent beam-like model and suggests its potential use for the seismic assessment of building structures. The low computational cost related to the beam-like model could be particularly advantageous for all the seismic vulnerability approaches requiring several nonlinear dynamic analyses, as those related to large scale applications, or those expressed in terms of probability of failure generally expressed in terms of fragility curves.

Modeling of Precast Building Frames for Seismic Response Analysis

Modeling of Precast Building Frames for Seismic Response Analysis