Journal articles: 'Load Based Testing'

1

Wang, Xingen, Bo Zhou, and Wei Li. "Model-based load testing of web applications." Journal of the Chinese Institute of Engineers 36, no. 1 (January 2013): 74–86. http://dx.doi.org/10.1080/02533839.2012.726028.

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Fuchs, P. A., G. A. Washer, S. B. Chase, and M. Moore. "Laser-Based Instrumentation for Bridge Load Testing." Journal of Performance of Constructed Facilities 18, no. 4 (November 2004): 213–19. http://dx.doi.org/10.1061/(asce)0887-3828(2004)18:4(213).

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Zuo, Huang, Yue Chun Zhang, Ping Liu, Wen Wang, and Shun Xiong. "Study on Loads of Accelerated Contact Fatigue Testing and its Application." Applied Mechanics and Materials 86 (August 2011): 680–83. http://dx.doi.org/10.4028/www.scientific.net/amm.86.680.

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For reducing the development time and cost, determining the load of accelerated contact fatigue testing of a multi-case and multi-stage drive train, multilevel design load method was used to calculate the pitting equivalent loads of gears according to the load spectrum. A reasonable load of pitting fatigue testing was determined after analyzing and studying the pitting equivalent loads of gears. Based on a reducer used for a cement mixer, the pitting equivalent loads of gears were calculated, and the load of pitting fatigue testing was determined. The damage ratios of gears were calculated by the pitting equivalent loads of gears and the testing load, separately, using software MASTA. The results from the load of pitting fatigue testing and the testing load were coincident.

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Cheng, Li, James E. Braun, and W. Travis Horton. "Load-based testing using a thermostat environment emulator." International Journal of Refrigeration 126 (June 2021): 109–22. http://dx.doi.org/10.1016/j.ijrefrig.2021.02.010.

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Ramakrishnan, Raghu, and Arvinder Kaur. "Little’s law based validation framework for load testing." Information and Software Technology 108 (April 2019): 88–98. http://dx.doi.org/10.1016/j.infsof.2018.11.007.

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Yu, Li Li, Xia Zhao, Chao Hui Ye, and Li Jie Yu. "A Web Load Testing Method Based on Performance Target." Applied Mechanics and Materials 380-384 (August 2013): 2187–91. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.2187.

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With the purpose of acquiring the Web system to work correctly under the guidance of software requirement, load testing is one of the important approaches. In this paper a web load testing based on performance target is proposed. Then several key points of achieving the load testing based on LoadRunner are discussed. At last combining a case study about the information management system software, Web load testing automation is achieved and testing results are analyzed.

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Anggriawan, Dimas Okky, Aidin Amsyar, Eka Prasetyono, Endro Wahjono, Indhana Sudiharto, and Anang Tjahjono. "Load Identification Using Harmonic Based on Probabilistic Neural Network." EMITTER International Journal of Engineering Technology 7, no. 1 (June 15, 2019): 71–82. http://dx.doi.org/10.24003/emitter.v7i1.330.

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Due to increase power quality which are caused by harmonic distortion it could be affected malfunction electrical equipment. Therefore, identification of harmonic loads become important attentionÂ in the power system. According to those problems, this paper proposes a Load Identification using harmonic based on probabilistic neural network (PNN). Harmonic is obtained by experiment using prototype, which it consists of microcontroller and current sensor. Fast Fourier Transform (FFT) method to analyze of current waveform on loads become harmonic load data. PNN is used to identify the type of load. To load identification, PNN is trained to get the new weight. Testing is conducted To evaluate of the accuracy of the PNN from combination of four loads. The results demonstrate that this method has high accuracy to determine type of loads based on harmonic load

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Azzam, Baher, Ralf Schelenz, Martin Cardaun, and Georg Jacobs. "From Simulations to Accelerated Testing: Design of Experiments for Accelerated Load Testing of a Wind Turbine Drivetrain Based on Aeroelastic Multibody Simulation Data." Applied Sciences 13, no. 1 (December 27, 2022): 356. http://dx.doi.org/10.3390/app13010356.

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The trend of increasing the power output and nominal load capacities of wind turbines (WT) over time has been driving the construction of testing facilities with increasing load capacities for testing WT drivetrain components prior to field deployment. Due to the high investment and operational costs of such facilities, a need exists to design accelerated tests that cover load situations corresponding to expected field conditions while maintaining high time-efficiency. This investigation addresses this need by presenting a methodology to achieve the following goals. Firstly, identifying ranges and combinations of WT 6-degree of freedom (6-DOF) rotor loads is to be expected in the field. This is achieved using aeroelastic multibody simulations (MBS) of an MBS WT model being subjected to simulated wind fields covering the design load cases outlined in the IEC 61400-1 standard and by analyzing the simulated time-series data to design accelerated tests that efficiently and realistically cover the design space of the variables, e.g., 6-DOF rotor loads, to be applied during WT drivetrain testing. The designed tests are to take place on a purpose-built test rig that allows for the application and control of the 6-DOF drivetrain input loads and rotational speed. Using the proposed method, accelerated tests were designed that efficiently cover load combinations within the realistic regions of the design space. A comparison with a full factorial design of experiments shows a significant (95+ %) reduction in total test time as well as the ability of the proposed method to help to avoid unsustainable and unrealistic load conditions within the design space that could result in costly, unintended drivetrain failures during testing.

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Kumar, Akash, Bing Yan, and Ace Bilton. "Machine Learning-Based Load Forecasting for Nanogrid Peak Load Cost Reduction." Energies 15, no. 18 (September 14, 2022): 6721. http://dx.doi.org/10.3390/en15186721.

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Increased focus on sustainability and energy decentralization has positively impacted the adoption of nanogrids. With the tremendous growth, load forecasting has become crucial for their daily operation. Since the loads of nanogrids have large variations with sudden usage of large household electrical appliances, existing forecasting models, majorly focused on lower volatile loads, may not work well. Moreover, abrupt operation of electrical appliances in a nanogrid, even for shorter durations, especially in “Peak Hours,” raises the energy cost substantially. In this paper, an ANN model with dynamic feature selection is developed to predict the hour-ahead load of nanogrids based on meteorological data and a load lag of 1 h (t-1). In addition, by thresholding the predicted load against the average load of previous hours, peak loads, and their time indices are accurately identified. Numerical testing results show that the developed model can predict loads of nanogrids with the Mean Square Error (MSE) of 0.03 KW, the Mean Absolute Percentage Error (MAPE) of 9%, and the coefficient of variation (CV) of 11.9% and results in an average of 20% daily energy cost savings by shifting peak load to off-peak hours.

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Bezboruah, Tulshi, and Abhijit Bora. "Performance Evaluation of Hierarchical SOAP Based Web Service in Load Balancing Cluster-Based and Non-Cluster-Based Web Server." International Journal of Information Retrieval Research 5, no. 4 (October 2015): 19–30. http://dx.doi.org/10.4018/ijirr.2015100102.

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Evaluating the implementation techniques of web service and analysing their performance in load balancing cluster-based and non-cluster-based web server is necessary from the perspective of web service developer, researchers as well as users. As such the authors propose to develop and implement a SOAP based hierarchical web service using load balancing cluster-based and non-cluster based Apache Tomcat web server to study the web service performance metrics. The performance of overall system is tested using the load testing tool Mercury Load runner and a comparative investigation is carried out using the stability, load and performance metrics of both services. In this paper, the authors present, in detail, the methodology of experiment, comparative testing results, and statistical analysis on performance metrics.

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Chu, Yun Xia, Yue Lin Zou, and Jun Zhang. "Intelligent Testing System for AC Load Based on PLC." Key Engineering Materials 620 (August 2014): 581–86. http://dx.doi.org/10.4028/www.scientific.net/kem.620.581.

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The backup power plays an important emergency supply role in industrial field and agricultural field. The emergency supply power (such as generator and Uninterrupted Power System etc.) is a standby state in most of the time. These devices only start to ensure electricity supply on the condition of power lose or power failure. It is difficult for users to know its real load performance. This paper designed a kind of intelligent AC (Alternating current) load test system based on PLC (Programmable Logic Controller) to solve the problem. There are signal acquisition part, the dummy load component and parameter display control part in testing load testing system, which can meet the general users of emergency power supply in daily inspection. We design the intelligent control for high performance and fine test users. The test results show that the intelligent AC load systems based on PLC can effectively detect power generation units and UPS emergency power supply in according with national standards.

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Jin, Wenming, Ju Qian, and Shuoyan Yan. "Shared-Mode Resource Allocation for Cloud-Based Load Testing." IEEE Access 8 (2020): 161894–907. http://dx.doi.org/10.1109/access.2020.3020863.

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Fageria, Pratibha, and Manju Kaushik. "Research of Load Testing and Result Based on Loadrunner." International Journal of Civil Engineering 1, no. 2 (April 25, 2014): 1–4. http://dx.doi.org/10.14445/23488352/ijce-v1i2p101.

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Xing, Hai Yan, Li Hong Zhang, Cheng Xu, and Xin Yu Chen. "Welded Joint Nonpenetration and Slag Inclusion Evaluation Based on MMM Signal Characteristic." Advanced Materials Research 189-193 (February 2011): 3355–58. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.3355.

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The metal magnetic memory (MMM) technology, a new nondestructive testing (NDT), has potentials of quantitative evaluation on welded joint defects. This paper investigates MMM signal quantitative characteristic of welded joint defects. Steel Q235 welded joint specimens, prefabricated with nonpenetration and slag inclusion, have been scanned by MMM testing instrument at 0kN, 150kN and 230kN tension loads on tensile machinery. For the nonpenetration specimens, MMM peak amplitude ΔHp and the peak width D adds with the increasing of tensile load, but gradient K varies a little. As for the slag inclusion specimens, the ΔHp and K enhances along with tensile load increasing, but the D varies a little. The X-ray testing results at 0kN, 150kN and 230kN tension loads show the validity of MMM signal characteristic. This means the feasibility of the weld qualitative and quantitative evaluation based on MMM method.

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Prisacari, Anna Agripina, and Jared Danielson. "Computer-based versus paper-based testing: Investigating testing mode with cognitive load and scratch paper use." Computers in Human Behavior 77 (December 2017): 1–10. http://dx.doi.org/10.1016/j.chb.2017.07.044.

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Behnamghader, Aliasghar, Reyhaneh Neghabat Shirazi, Alain Iost, and Denis Najjar. "Surface Cracking and Degradation of Dense Hydroxyapatite through Vickers Microindentation Testing." Applied Mechanics and Materials 66-68 (July 2011): 614–19. http://dx.doi.org/10.4028/www.scientific.net/amm.66-68.614.

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Surface degradation and cracking of dense hydroxyapatite were evaluated through Vickers micro indentation using indentation loads ranged from 25 gf to 2000 gf. Crack lengths, imprint diameters and the number of lateral cracks and chips were measured using SEM. The crack length-indentation load data were analyzed with regard to the specific relations of Palmqvist and fully developed radial cracks. Crack type transition load from Palmqvist to median crack was experimentally assessed through serial sectioning technique. The analytical estimated transition load, based on the theoretical relation of the indentation load and crack lengths showed a good agreement with one obtained from experimental itinerary. Palmqvist and median cracks were identified in low and medium indentation loads, respectively. High indentation load could also lead to the formation of lateral cracks and chips. The tendency for lateral cracking was evaluated taking into account the number of lateral cracks and chips. The chips were found to be appeared just after test in higher indentation load, whereas in medium loads they could be detectable only after several weeks.

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Sołkowski, Juliusz, and Dawid Siemieński. "Testing and evaluation of railway pavement construction stiffness based on a new testing method." Transportation Overview - Przeglad Komunikacyjny 2018, no. 6 (June 1, 2018): 32–42. http://dx.doi.org/10.35117/a_eng_18_06_04.

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This project is based on search for the method of measuring and evaluation the railway pavement construction. The authors note some analogies between road and railway, both in terms of construction and the dynamic load. Already in the 1960s a method for measuring road pavement deflections under dynamic load was developed using Falling Weight Deflectometer. During years the device and the results analysis method were developed and currently commonly used. The FWD device was adapted for use on railway pavement construction. The first tests were done in the field and have brought reliable results. The device and measuring and pavement evaluation methods are under development.

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Sike, Wang, Guo Yu, Li Jun, Xia Tian, and Lei Ming. "Gateway Electric Energy Meter Measurement System Based on Independent Load Control." MATEC Web of Conferences 175 (2018): 03030. http://dx.doi.org/10.1051/matecconf/201817503030.

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In order to meet the efficiency and timeliness measurement requirements for electric energy meters with different specifications in gateway energy meter testing laboratory, a new testing system based on multithreading technique is proposed here. Through identifying the different wiring modes of electric meters, integrating with newly designed CT based on zero-flux compensation principle and applying creative multi-channel load control for different tap positions, the system can provide differentiated testing loads for different meters at the same time. Meanwhile, electric energy pulses required by different electric energy meters can be worked out by one standard meter. Consequently, completely independent measurement for different meters will be achieved with improved timeliness substantially. Through simulation tests for different electric energy meters, and comparison for calculated testing time, the initial design purposes are tested and verified.

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Raza, Ali, Asif M. Qureshi, Muhammad Q. Saleem, and Sajjad Maqbool. "Phagocytosis-based camera-in-situ method for pile load testing." Automation in Construction 45 (September 2014): 33–41. http://dx.doi.org/10.1016/j.autcon.2014.04.011.

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Jeong, In Wha. "DC-Link Capacitor Voltage Balancing Control of a Five-Level Regenerative AC Electronic Load Using One-Cycle Control." Energies 14, no. 19 (September 24, 2021): 6101. http://dx.doi.org/10.3390/en14196101.

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High voltage electric power equipment requires rigorous regulation testing to specific standards which ensure proper and safe operation in the grid. Manufacturers conduct these tests in order to prove standard compliance and product liability. Variable linear or nonlinear loads are necessary for testing medium voltage (MV) high power AC power converters. Generally, those AC power converters or power supplies require performance validation, burn-in and/or lifetime testing under different load conditions, defined by the end-user or standards for the given applications. For flexible and efficient MV verification testing, this paper presents a five-level multilevel converter-based MV regenerative AC electronic load with one-cycle control (OCC), which is based on five-level diode-clamped multilevel converters with back-to-back structure and can emulate any impedance load. In this paper, especially the dc-link capacitor voltage balance of the proposed multilevel MV regenerative AC load is deeply analyzed. Simulation and experimental results are presented to verify the dc-link voltage balance performance of the proposed multilevel MV regenerative AC electronic load.

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Wang, Jing-Fong, Tzu-Hua Wang, and Chao-Hsien Huang. "Investigating Students’ Answering Behaviors in a Computer-Based Mathematics Algebra Test: A Cognitive-Load Perspective." Behavioral Sciences 12, no. 8 (August 18, 2022): 293. http://dx.doi.org/10.3390/bs12080293.

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Computer-based testing is an emerging method to evaluate students’ mathematics learning outcomes. However, algebra problems impose a high cognitive load due to requiring multiple calculation steps, which might reduce students’ performance in computer-based testing. In order to understand students’ cognitive load when answering algebra questions in a computer-based testing environment, three perspectives, element interactivity, practice effect, and individual differences, were investigated in this study. Seven levels of algebra exam questions were created using unary and simultaneous linear equations, and the inverse efficiency scores were employed as a measure of cognitive load in the study. Forty undergraduate and graduate students were tested. There were four findings: (1) As the element interactivity of test materials increased, the cognitive load increased rapidly. (2) The high-efficiency group had a lower cognitive load than the low-efficiency group, suggesting that the high-efficiency group had an advantage in a computer-based testing environment. (3) “Practice” has a considerable effect on reducing cognitive load, particularly in level 6 and 7 test items. (4) The low-efficiency group can reduce but not eliminate the gap with the high-efficiency group; they may require additional experience in a computer-based testing environment in order to improve reducing their cognitive load.

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Hwang, Kitae, In Hwan\ Jung, and ae Moon Lee. "Monitoring of MQTT-based Messaging Server." Webology 19, no. 1 (January 20, 2022): 4724–35. http://dx.doi.org/10.14704/web/v19i1/web19316.

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In the messaging server where many devices send and receive messages, the ability to monitor the performance of the server and characteristics of the messaging is essential. This paper decides MQTT as the messaging protocol, and analyzes and defines key parameters that show the performance of the MQTT server and the characteristics of MQTT communication like MQTT message topics. In addition, this paper built an MQTT messaging server for testing by using Mosquitto as a MQTT broker and a separate monitoring system to monitor defined key parameters. In this paper, the system for monitoring the performance of the MQTT messaging server was built into three parts: a dashboard server, a monitoring application, and a test load generator. The test load generator is configured to generate a large amount of MQTT message load using 11 Raspberry PIs. The monitoring application was developed and installed on the MQTT server computer and periodically stored the server's performance and the MQTT message-related parameters processed by Mosquitto in the dashboard server's DB. The dashboard server was developed as a web server and implemented so that the administrator can view the data stored in the DB through a web browser in real time. Through experiments that generate various loads in the test load generator, it has been confirmed that the monitoring system operates normally. The monitoring system built in this paper is expected to be a good model of the monitoring system to be built together when developing an MQTT-based messaging server.

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SALES, Mauricio Martines, Monica PREZZI, Rodrigo SALGADO, Yoon Seok CHOI, and Jintae LEE. "LOAD-SETTLEMENT BEHAVIOUR OF MODEL PILE GROUPS IN SAND UNDER VERTICAL LOAD." Journal of Civil Engineering and Management 23, no. 8 (November 20, 2017): 1148–63. http://dx.doi.org/10.3846/13923730.2017.1396559.

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Model pile load testing is effective to study the load-settlement behaviour of pile foundations given the controlled environment in which the testing is done. This paper reports a testing program in a large calibration chamber involving individual piles and pile groups installed in sand samples of three different densities. Tests on both nondisplacement and driven piles are evaluated to assess the influence of the pile installation process on pile load-settlement response. A method is proposed to predict the load-settlement response of a pile group based on the response of a single pile. The method is shown to produce estimates that are in good agreement with measurements. The influence of pile group configuration, pile spacing, soil density and method of pile installation is discussed.

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Aguilar, Carlos V., David V. Jáuregui, Craig M. Newtson, Brad D. Weldon, and Tamara M. Cortez. "Load Rating a Prestressed Concrete Double T-Beam Bridge without Plans by Field Testing." Transportation Research Record: Journal of the Transportation Research Board 2522, no. 1 (January 2015): 90–99. http://dx.doi.org/10.3141/2522-09.

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Bridges with no design plans are an issue in New Mexico because of the many that exist throughout the state. Conventional load rating techniques cannot be used because these bridges have limited or no design documentation. This lack of information has created uncertainties regarding the load-carrying capacity of these structures. Only a few states have formal procedures on how these particular bridges should be load rated. A project was conducted for the New Mexico Department of Transportation to develop a procedure for load rating bridges without plans, including prestressed concrete bridges. In accordance with the AASHTO Manual for Bridge Evaluation, a prestressed concrete double T-beam bridge was evaluated with advanced analyses and experimental methods (including load testing and nondestructive material evaluation techniques). A four-step load rating procedure was implemented that included estimating the prestressing steel by Magnel diagrams, verifying the estimate with a rebar scanner, testing the bridge at both diagnostic and proof loads based on strain measurements, and using the proof test results to rate the bridge. Rating factors and posting loads were determined for AASHTO and New Mexico legal loads. Because of the poor condition of the shear keys (some of which were broken), it is shown that the load distribution between beams was adversely affected and the bridge should be load posted.

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Deng, Ming, Lei Wang, Jianren Zhang, Rei Wang, and Yanhong Yan. "Probabilistic model of bridge vehicle loads in port area based on in-situ load testing." IOP Conference Series: Earth and Environmental Science 94 (November 2017): 012205. http://dx.doi.org/10.1088/1755-1315/94/1/012205.

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Fu, Zhi Hao, and Yuan Sun. "PID control strategy of wind transmission chain based on particle swarm optimization." Journal of Physics: Conference Series 2355, no. 1 (October 1, 2022): 012058. http://dx.doi.org/10.1088/1742-6596/2355/1/012058.

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Abstract Wind turbine transmission chain is the key component of wind turbine to bear various loads, and its working characteristics are an important basis for testing the stability, reliability and safety of wind turbine. Aiming at the transmission chain system, a load simulation technology for ground test system of 1.5MW wind turbine transmission chain was proposed. According to its performance and requirements, a hydraulic loading system with 6-dOF load was designed. Hydraulic loading system is designed according to wind load. Through the mechanism method to establish its mathematical model, particle swarm optimization algorithm is easy to fall into the local optimal solution, using quantum particle swarm optimization algorithm, through Matlab/Simulink load simulation of the hydraulic loading system, the results show that the hydraulic loading system has a good tracking and reproduction of wind load

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Chang, Kurng. "Structural Response Loads in Force-Limited Vibration Testing." Journal of the IEST 45, no. 1 (September 14, 2002): 129–35. http://dx.doi.org/10.17764/jiet.45.1.bv71nq036p238625.

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Flight equipment is exposed to random vibration excitations during launch and is functionally designed to survive a shaker random vibration test. In the test, the random vibration design levels will be applied at the equipment-mounting interface and will be force limited to reduce over-testing at shaker hardmount resonance frequencies. As is commonly practiced for heavier equipment, the equipment also is designed to the structural flight limit load. The philosophy of the Limit Load Factors (LLFs) or so-called the Mass Acceleration Curve (MAC) has been adopted over many years for use in the preliminary structural design of spacecraft and flight equipment. The purpose of the work presented herein is to discuss the results of force limit notching during vibration testing with respect to the traditional limit load design criteria. By using a single-degree-of-freedom (SDOF) system approach, this work shows that with an appropriate force specification the notched response due to force limiting will result in loads comparable with the structural design limit criteria. A simplified formula is presented to predict the test load limits, based only upon estimates for the first significant resonance of the equipment and the semi-empirical force specification factor, C2.

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Zhou, Kun, Linhua Chen, and Shanshan Yu. "Vision-based Deformation Measurement for Pile-soil Testing." MATEC Web of Conferences 275 (2019): 03009. http://dx.doi.org/10.1051/matecconf/201927503009.

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Image measurement technology has been widely used in monitoring the deformation of the soil field around the pile with its advantages of no damage, no contact, full-field measurement, no added quality and high sensitivity. But there are few researches on image-based bearing deformation measurement of the pile. Through an indoor pile-soil semi-model test, the rigid body displacement and load-bearing deformation of a new type of prefabricated steel tube pile foundation under horizontal load was measured based on image features. In this study, the concept of optical extensometer is first applied to the measurement of local average strain of a non-uniform deformed structure. Based on an improved feature point tracking algorithm SURF-BRISK, non-contact measurement of tiny strain of pile body is realized. In addition, based on DIC technology, this study also obtained the progressive development of displacement field of soil around pile. The above work fully reflects the non-contact convenience and full-field richness of the optical measurement method compared with the traditional measurement method.

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Deng, Miao Yi, and Fuen Li. "Study and Application of Bridge Structure Finite Element Model Updating Based on Static-Load Testing." Advanced Materials Research 201-203 (February 2011): 2672–78. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.2672.

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A method for continuous box-girder bridge structure finite element (FE) model updating based on static-load testing is proposed. The procedure includes field static-load testing, FE modeling, FE model (parameter) updating, etc. Based on this procedure, the structure FE model updating for an expressway 5-span pre-stressed concrete continuous box-girder bridge is conducted. And the bridge structure static FE model, which is consistent with the static-load testing actual measure response, is gained. The updated FE model (parameter) is foundation of structural performance evaluation for the bridge.

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Khan, Rijwan, and Mohd Amjad. "Performance testing (load) of web applications based on test case management." Perspectives in Science 8 (September 2016): 355–57. http://dx.doi.org/10.1016/j.pisc.2016.04.073.

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Dillenseger, Bruno. "CLIF, a framework based on Fractal for flexible, distributed load testing." annals of telecommunications - annales des télécommunications 64, no. 1-2 (November 18, 2008): 101–20. http://dx.doi.org/10.1007/s12243-008-0067-9.

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Hughes, Jake Edmond, Yeesock Kim, Tahar El-Korchi, and David Cyganski. "Radar-based impact load prediction for damage mitigation of infrastructure." Journal of Vibration and Control 23, no. 12 (September 9, 2015): 1908–24. http://dx.doi.org/10.1177/1077546315603856.

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The application of smart control technology to both aging and new infrastructure is essential to extending service life, increasing life safety, and decreasing repair and replacement costs. One area of control technology research for civil engineering structures that has received little attention historically is that of high-impact loads, such as collision events. The dissipation of impact energy using smart control devices, such as magnetorheological (MR) dampers, leads to less plastic deformation and damage, and a lower likelihood of collapse in civil engineering structures. Due to the short duration and high variability in magnitude of potential impact loads, the issue of sub-optimal controller performance arises. In order to boost controller performance and improve the effectiveness of the control system, a radar-based impact load identifier is proposed. This radar-based impact load identifier will be used to estimate impact loads from imminent impacting objects, for example vessels and trucks, thus providing input information to the control system before the impact actually occurs. This paper presents the characterization and validation, through laboratory tests, of one part of the radar-based impact load identifier, the range and velocity estimation of the incoming moving objects. The range and velocity information are then used to direct structural control based on laboratory impact tests. An ultrawideband monostatic pulsed radar is used for range and velocity measurements of a laboratory-scale impacting vehicle. The range and velocity measurements obtained from the radar scans are verified using physical measurements and control testing. The tests showed great accuracy for both range and velocity with less than 3% error for each measurement and demonstrated structural control based on these measurements. It is shown from control system testing that the proposed approach is effective in reducing the structural impact responses by 11–30%, depending on the performance index, for pre-impact structural stiffening with passive control of MR dampers.

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Ataei, Shervan, Meysam Jahangiri Alikamar, and Vahid Kazemiashtiani. "Evaluation of axle load increasing on a monumental masonry arch bridge based on field load testing." Construction and Building Materials 116 (July 2016): 413–21. http://dx.doi.org/10.1016/j.conbuildmat.2016.04.126.

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Dai, Dong, Du Chen, Shumao Wang, Song Li, Xu Mao, Bin Zhang, Zhenyu Wang, and Zheng Ma. "Compilation and Extrapolation of Load Spectrum of Tractor Ground Vibration Load Based on CEEMDAN-POT Model." Agriculture 13, no. 1 (January 2, 2023): 125. http://dx.doi.org/10.3390/agriculture13010125.

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Effective indoor testing on a four-poster rig of agricultural machinery should mimic the real-world environment while the machinery is in farming and transportation. The emerging load spectrum extrapolation and compilation are capable of speeding up the use of the indoor vibration testing of tractors. However, most ground load spectrum studies consider a particular type of ground rather than all the rough farmland conditions that tractors experience daily. Such a problem inevitably raises doubts about validating the load spectrum-based fatigue durability and reliability testing of tractors. For a remedy, this article proposes a CEEMDAN-POT (Peak Over Threshold) model to comprehensively build a full life-cycle ground load spectrum of tractor vibration with six ground conditions and different field operations. The study acquires the real four vertical acceleration signals from the front and rear axles of the tractor to collect representative vibration load data. Furthermore, the study refines the measured load data by proposing a CEEMDAN-Wavelet threshold method, which is proved to be effective for the load signal decomposition and denoising. Lastly, the study presents a time domain extrapolation method, integrating the sample principle of the POT model, the proper parameter estimation with the Generalized Pareto Distribution (GPD) function, and the POT super-threshold model. The statistical analysis implies that the produced load spectrum fully preserves the statistical features observed in the original one. After extrapolation, the overall distribution of the rainflow matrix becomes more consistent while the mean and amplitude of the spectrum data increase. This study unifies a load spectrum of tractors operating and transporting on various farm ground conditions, providing the real load data of the indoor four-poster rig test.

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MASCENIK, JOZEF, and SLAVKO PAVLENKO. "CONTROLLED TESTING OF BELT TRANSMISSIONS AT DIFFERENT LOADS." MM Science Journal 2021, no. 6 (December 15, 2021): 5497–501. http://dx.doi.org/10.17973/mmsj.2021_12_2021045.

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The presented paper provides the alternative options for determining the condition of belt gear based on the testing and monitoring. In order to carry out experimental measurements, a newly developed device for testing, monitoring and diagnostics of belt drives was designed, as well as the possibility of determination of limit states by extreme loads. The designed measuring stand allows to determine the point of destruction of the belt for an extreme load. The process of the belt measurement was to set the predetermined input revolutions of the driving motor by means of the Altivar 71 (FM1) frequency inverter connected to the driving electric motor. The next step in defining the input parameters was to set the load on the driven electric motor. The load on the driven motor was achieved by the torsional moment set by means of the Altivar 71 (FM2) frequency inverter connected to the driven electric motor. In the paper, the analytical calculation is processed. The article mainly points to the innovation of the stand for testing belt transmissions.

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Lisowski, Filip, and Edward Lisowski. "Testing and Fatigue Life Assessment of Timber Truck Stanchions." Applied Sciences 10, no. 17 (September 3, 2020): 6134. http://dx.doi.org/10.3390/app10176134.

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Components of transport trucks are subjected to dynamic cyclic loads. The magnitude of these loads depends on road conditions and cargo mass. Cyclic loads can cause fatigue failure at stress levels significantly below the yield strength of the material. When calculating fatigue, it is necessary to determine the actual loads acting on the structure under working conditions. In this study, stanchion displacements of overloaded timber trucks were measured under both static and dynamic loads. For the specified mass of timber, a history of dynamic loads acting on the stanchion was obtained. Then, based on the finite element analysis, stress concentration points were determined within the base material and welded joints of the stanchion. The history of maximum stresses at concentration points was determined. Stress ranges and mean stresses for the load history were calculated using the rainflow fatigue cycle counting method. Repeats to failure were determined on the basis of the Palmgren–Miner cumulative damage rule and the modified Goodman correction for the points with the highest stress level. Experimental investigation of the actual load history of the stanchion of significantly overloaded timber truck allowed to determine the mileage to potential failure.

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Zhao, Guiqing. "Research on Inspection Method of Dynamic Load of Truck by Using EWT." International Journal of Information Systems and Supply Chain Management 11, no. 1 (January 2018): 49–64. http://dx.doi.org/10.4018/ijisscm.2018010105.

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The article provides a new method for dynamic real-time detection of vehicle loads, and a useful technical reference for further improving the driving safety of the vehicle. The dynamic monitoring of vehicle load is of great significance to stable driving. In order to resolve this problem, we present an algorithm that can calculate vehicle load on the basic of empirical mode transform (EWT) and a corresponding vehicle load dynamic testing platform. The relationship between the vehicle load and the suspension variables is the foundation of realizing load detection. To obtain it, we establish a two-degree-of freedom suspension dynamic model and analyze the dynamic characteristics of the suspension under various vehicle speeds and loads. We design a dynamic load detection device with overload protection to collect the dynamic signal of vehicle. The data processing algorithm of the vehicle load dynamic detection device is constructed based on EWT. In order to verify the effectiveness of the device, a model truck is taken as the test vehicle. Based on the DSP chip, the vehicle load dynamic testing platform is developed. In order to test the accuracy of the system, the calculation accuracy of the system is tested with different load at different speeds. The experimental results show that the system exhibits a high accuracy in the measurement experiment.

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Wang, Xing Guo. "Quality Testing of the Chrome Coating Based on Acoustic Emission Technology." Applied Mechanics and Materials 253-255 (December 2012): 399–402. http://dx.doi.org/10.4028/www.scientific.net/amm.253-255.399.

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A assessment method on quality detected system was developed on cylinders inner wall coating through the hydraulic radial expansive load system and acoustic emission testing technology,. Put double probes linear position principle and uniform motion of load system together, and make curved positioning come true based on the technical principle of locating acoustic emission source. The disadvantage was solved that double probes can’t make acoustic emission source planar positioning. The result showed that this system can provide a precise identification and location; it has fast testing velocity and portable device.

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Wang, Da Peng, and Shi Zhu Tian. "Pseudo-Dynamic Testing Method Based on External Displacement Control." Applied Mechanics and Materials 204-208 (October 2012): 2428–32. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.2428.

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In order to accelerate the velocity and improve the accuracy of the pseudo-dynamic testing，the external displacement control method is put forward based on the hardware control. The internal displacement sensor of the actuator is invalid on control and substituted by the LVDT displacement sensor connected with the specimen. The process of the feedback displacement and command error compensation is quickly implemented by the internal closed-loop control of the actuator. Compared with the iteratively approximate load control, this method not only makes the testing velocity fast, but also enables the error between command and feedback to be “zero”. The fast pseudo-dynamic testing about a cantilever beam is carried out by applying appropriate PID parameters of the actuator. The testing result shows that although this method has rather high requirements in the control system and electro-hydraulic servo load device, and the risk to some extent, the fast response of the actuator can be firmed by applying appropriate PID control parameters. This method provides a fast testing technology for velocity-dependent structures or specimens.

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Wu, Ji Ping, and You Xing Cai. "Testing and Error Analysis of some Structure’s Impact Load." Advanced Materials Research 139-141 (October 2010): 2473–77. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.2473.

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The shock response of single freedom system was studied based on impact theory. The shear blade of some merchant shearing machine was selected as the object. The static calibration and impact load testing was carried on the object. Based on the impact theory and finite element technology, the feasibility of the testing scheme and the influence of the shock wave shape on the testing accuracy were discussed. The results show that for the shear blade, when the impact load time history is 50ms and the natural frequency is 2848Hz, there only 0.42% difference between the maximum dynamic response and the static calibrated response. So it is practicable to use the static calibrated results to decide the relationship of the impact load and strain.

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Moayedi, Hossein, and Amir Mosavi. "Double-Target Based Neural Networks in Predicting Energy Consumption in Residential Buildings." Energies 14, no. 5 (March 1, 2021): 1331. http://dx.doi.org/10.3390/en14051331.

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A reliable prediction of sustainable energy consumption is key for designing environmentally friendly buildings. In this study, three novel hybrid intelligent methods, namely the grasshopper optimization algorithm (GOA), wind-driven optimization (WDO), and biogeography-based optimization (BBO), are employed to optimize the multitarget prediction of heating loads (HLs) and cooling loads (CLs) in the heating, ventilation and air conditioning (HVAC) systems. Concerning the optimization of the applied algorithms, a series of swarm-based iterations are performed, and the best structure is proposed for each model. The GOA, WDO, and BBO algorithms are mixed with a class of feedforward artificial neural networks (ANNs), which is called a multi-layer perceptron (MLP) to predict the HL and CL. According to the sensitivity analysis, the WDO with swarm size = 500 proposes the most-fitted ANN. The proposed WDO-ANN provided an accurate prediction in terms of heating load (training (R2 correlation = 0.977 and RMSE error = 0.183) and testing (R2 correlation = 0.973 and RMSE error = 0.190)) and yielded the best-fitted prediction in terms of cooling load (training (R2 correlation = 0.99 and RMSE error = 0.147) and testing (R2 correlation = 0.99 and RMSE error = 0.148)).

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Xu, Wei, Zhenshu Wang, Jingyu Sun, and Xun Zhong. "Research on Load Characteristic Data Clustering Based on Transfer Learning." Journal of Physics: Conference Series 2166, no. 1 (January 1, 2022): 012008. http://dx.doi.org/10.1088/1742-6596/2166/1/012008.

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Abstract As power system informatization developed, the distribution network side has accumulated a lot of load data. As an effective data processing method, cluster analysis is helpful to mine the valuable information hidden in the load data and extract accurate load characteristics. In order to extract intuitive and effective load characteristics, a load characteristic data clustering method based on transfer learning is proposed, which deeply studies the problem of ignoring the data distribution difference between training set and testing set in the traditional clustering process. Case studies verify the efficiency and effectiveness of the algorithm.

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Chen, Zhi Peng, Xiao Yi Jin, Chun Yun Ji, Chuan Wang, and Jian Liu Zhu. "Research on Friction Property of Pin on Disc and Analysis of Wear Mechanism Based on MMW-1A Friction and Wear Testing Machine." Key Engineering Materials 764 (February 2018): 86–92. http://dx.doi.org/10.4028/www.scientific.net/kem.764.86.

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Friction and wear are very important in mechanical design. This paper studies the friction and wear characteristics of 45 steel under oil lubrication. The sliding friction and wear experiment was carried out with the pin plate friction pairs on the MMW-1A friction and wear test machine. Researching the influence of velocity on friction factor under the same load, the relation between wear and load and wear analysis under the same speed different loads. The results showed that under the same load and with the increase of velocity, the friction factor had a gradually decreasing trend. When some of the parameters were certain, the wear volume and the loading force was roughly linear relation. Pitting occurred when the load increased.

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Cheng, Li, Parveen Dhillon, W. Travis Horton, and James E. Braun. "Automated laboratory load-based testing and performance rating of residential cooling equipment." International Journal of Refrigeration 123 (March 2021): 124–37. http://dx.doi.org/10.1016/j.ijrefrig.2020.11.016.

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Ling-Zhi Yi, Ling-Zhi Yi, Xi-Meng Liu Ling-Zhi Yi, Guo-Yong Zhang Xi-Meng Liu, Hui-Na Song Guo-Yong Zhang, and Ning Liu Hui-Na Song. "An Non-Intrusive Load Event Detection Approach Based on CEEMDAN-WTD-F Test." 電腦學刊 33, no. 6 (December 2022): 021–36. http://dx.doi.org/10.53106/199115992022123306002.

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<p>To improve the perception of the switch state of the electrical equipment and realize the identification of the non-intrusive load switching process more accurately, a non-intrusive load event detection method based on the CEEMDAN-WTD-F test is proposed in this paper. Firstly, the adaptive median filter is used to reduce the noise fluctuation of power data of electric equipment and the discrete sequence derivative is used to reduce turn-on transition time for individual loads. Then, based on the principle of decomposition denoising and statistical testing, Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) and Wavelet Threshold De-noising (WTD) are used to process the input signal, and then the F test is used to determine whether an event occurs. Then, the proposed detection method is verified on the BLUED public data set, and a comparison experiment is carried out with the existing detection algorithm. The experimental results fully show that the proposed method has a lower missed detection rate and false detection rate than other detection algorithms, and the detection precision rate, recall rate, and F1 value are higher than 97%.</p> <p> </p>

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Zhu, Hua Ji, and Hua Rui Wu. "Study and Improvement of a Web Application Load Testing Model." Applied Mechanics and Materials 321-324 (June 2013): 2969–73. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.2969.

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As an important indicator of Web application performance testing - load capacity is a key factor to judge the merits of the Web application performance, load testing model is an important premise to accurately obtain the Web applications load capacity; This article is based on the model of user groups, Through further analysis of the general user behavior , user groups model is been improved properly. The practical application shows that the improved model more realistically simulate real user behavior, and make the data more statistical significance, which can more accurately predict the performance of web applications. Keywords: Web applications, load capacity, performance testing, load testing, model

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Fu, De Cheng, Yu Hui Wen, and Lei Wang. "Static and Dynamic Testing Study on Mechanical Behavior of Longtan Bridge." Applied Mechanics and Materials 684 (October 2014): 100–104. http://dx.doi.org/10.4028/www.scientific.net/amm.684.100.

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To assess the carrying capacity and reliability of the-Longtan Bridge, applied static load in the middle of the bridge step by step, then collected strain and deflection data of the beam. In order to understand the working principle of a bridge under dynamic loads, dynamic load test - Vehicle traffic test and fluctuation test t was performed, and vibration frequency data was collected. This paper described the basic principles of the bridge static and dynamic tests, and introduced the program of the experiment. Based on the test data, the static and dynamic mechanism of the bridge was discussed, the conclusion provides the basis for further study of bridge mechanism of the mechanical.

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Song, Jung Han, and Hoon Huh. "Influence of Tensile Speeds on the Failure Loads of the DP590 Spot Weld under Various Combined Loading Conditions." Advances in Materials Science and Engineering 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/297915.

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This paper is concerned with the evaluation of the dynamic failure load of the spot weld under combined axial and shear loading conditions. The testing fixture is designed to impose the combined axial and shear load on the spot weld. Using the proposed testing fixtures and specimens, quasi-static and dynamic failure tests of the spot weld are conducted with seven different combined loading conditions. The failure load and failure behavior of the spot weld are investigated with different loading conditions. Effect of tensile speeds on the failure load of the spot weld, which is critical for structural crashworthiness, is also examined based on the experimental data. The failure loads measured from the experiment are decomposed into the two components along the axial and shear directions and failure contours are plotted with different loading speeds. Dynamic sensitivities of failure loads with various combined loading conditions were also analyzed. Experimental results indicate that the failure contour is expanded with increasing loading speeds and failure loads show similar dynamic sensitivity with respect to the loading angles.

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Abbas, Rabiya, Zainab Sultan, and Shahid Nazir Bhatti . "Comparative Study of Load Testing Tools: Apache JMeter, HP LoadRunner, Microsoft Visual Studio (TFS), Siege." Sukkur IBA Journal of Computing and Mathematical Sciences 1, no. 2 (December 31, 2017): 102. http://dx.doi.org/10.30537/sjcms.v1i2.24.

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Software testing is the process of verifying and validating the user’s requirements. Testing is ongoing process during whole software development. Software testing is characterized into three main types. That is, in Black box testing, user doesn’t know domestic knowledge, internal logics and design of system. In white box testing, Tester knows the domestic logic of code. In Grey box testing, Tester has little bit knowledge about the internal structure and working of the system. It is commonly used in case of Integration testing.Load testing helps us to analyze the performance of the system under heavy load or under Zero load. This is achieved with the help of a Load Testing Tool. The intention for writing this research is to carry out a comparison of four load testing tools i.e. Apache JMeter, LoadRunner, Microsoft Visual Studio (TFS), Siege based on certain criteria i.e. test scripts generation , result reports, application support, plug-in supports, and cost . The main focus is to study these load testing tools and identify which tool is better and more efficient . We assume this comparison can help in selecting the most appropriate tool and motivates the use of open source load testing tools.

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McVay, Michael C., Ralph D. Ellis, Bjorn Birgisson, Gary R. Consolazio, Sastry Putcha, and Sang Min Lee. "Load and Resistance Factor Design, Cost, and Risk: Designing a Drilled-Shaft Load Test Program in Florida Limestone." Transportation Research Record: Journal of the Transportation Research Board 1849, no. 1 (January 2003): 98–106. http://dx.doi.org/10.3141/1849-12.

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Currently there are few if any guidelines on estimating the number of load tests in the design of drilled-shaft foundations in Florida limestone. For instance, for many sites there may be a similar number of field load tests but a significantly different number of design shafts. Moreover, little if any information exists on risk or reliability versus cost of drilled-shaft foundations or on the cost of field load testing. The collection of a large database of drilled-shaft tests (more than 25 with Osterberg and Statnamic devices), in situ laboratory data, drilled-shaft construction costs, and field load testing costs for Florida limestone is reported on. From the field load tests, the average unit skin friction for various sites was found, as well as the predicted values based on the Florida Department of Transportation recommended design approach. Next, using load and resistance factor design (LRFD), the resistance (ϕ) values were found for various reliabilities (risk or probability of failure). Once the factored design loads were known (from plans), drilled-shaft lengths were estimated on the basis of the computed LRFD ϕ-values for different reliabilities (i.e., risk). From the linear length of the designed shaft as well as the expected cost per meter, a plot of total foundation cost versus reliability (risk) was generated for each site. On the basis of the latter plot, acceptable risk, and the cost of field load testing (bid and itemized), the designer can identify the cost savings of load testing and the appropriate number of tests to be performed.

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Journal articles on the topic 'Load Based Testing'

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