scholarly journals Research of Vibrations of an Armoured Personnel Carrier Hull with FE Implementation

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6807
Author(s):  
Zdzisław Hryciów ◽  
Jerzy Małachowski ◽  
Piotr Rybak ◽  
Andrzej Wiśniewski

Modern wheeled armoured vehicles can perform a variety of tasks, making the development of weapon systems that can be safely and effectively integrated with the vehicle structure an area of interest. Due to the cost of implementing new models, it is more economical to test potential configurations using numerical methods, such as the finite element method. The numerical model has been validated to confirm the reliability of the obtained results. Modal tests were also performed using four configurations to identify the frequency and mode shape of natural vibrations occurring within the support structure. In an experimental setting, hull vibrations were forced using the modal hammer testing method. The modal assurance criterion (MAC) and the authors’ procedure were used to confirm the experimental and numerical test results. Additional testing in the form of impact loads was carried out for turret-containing structures. Structural strain at indicated points and forces transmitted by brackets to the bottom of the hull were compared.

2019 ◽  
Vol 4 (2) ◽  
pp. 176-183
Author(s):  
Ponco Wali

Testing repeat electronic scales with non-automatic scales technical requirements so far is fairly long if not using a calculator or computer. The aim of this research is to compare the repeatability testing method of electronic scales using methods according to the technical requirements of non-automatic scales and the Australian NMI method, both of which refer to OIML R76 in determining the validity or cancellation of electronic scales repeatability testing. This research method is done through repeat testing on 3 samples of electronic scales, then on each electronic scale 2 test methods are performed. The conclusion is that the electronic scales repeatability testing uses the non-automatic scales technical requirements method and the Australian NMI method has some differences although both refer to OIML R76. These differences include several points, namely the charge used, the method of adding additions, the formula for determining electronic scales, and different test results. The Australian NMI method is deemed to make it easier and more time efficient compared to the non-automatic weighing technical requirements method.


Author(s):  
P. Thibaux ◽  
J. Van Wittenberghe ◽  
E. Van Pottelberg ◽  
M. Van Poucke ◽  
P. De Baets ◽  
...  

Tubular joints are intensively used in off-shore structures for shallow waters. Depending on the sea conditions and the type of structure, the design can be fatigue driven. This is particularly the case for off-shore wind turbines, where turbulences are generating a fatigue loading. Any improvement of the fatigue performance of the tubular joint would be beneficial to reduce the weight and the cost of the structure. To assess efficiently the fatigue resistance of the tubular joint, a testing method has been developed based on the resonance principle. The complete circumference of the welded joint can be loaded, successively in the in-plane and out-of-plane modes at a frequency close to 20Hz. Finite element computations were used to investigate the feasibility of the concept. Then, an X-node was made and successfully tested to investigate the stress distribution along the weld. The experimental results were compared with finite element computations, giving a good agreement.


Author(s):  
Leila Ladani ◽  
Lalit Roy

Additive Layer Fabrication, in particular Electron Beam Additive Fabrication (EBAF), has recently drawn much attention for its special usability to fabricate intricately designed parts as a whole. It not only increases the production rate which reduces the production lead time but also reduces the cost by minimizing the amount of waste material to a great extent. Ti6Al4V is the most common type of material that is currently being fabricated using EBAF technique. This material has been used in aerospace industry for several reasons such as excellent mechanical properties, low density, great resistance to corrosion, and non-magnetism. The effects of build direction of layers (namely, addition of layers along one of the x, y & z directions with respect to the build table) and the anisotropy effect caused by it has not been explored vigorously. This anisotropy effect has been investigated in this work. Different mechanical properties such as Yield Strength (YS), Ultimate Tensile Strength (UTS), and Modulus of Elasticity (E) of these three types of Ti6Al4V are determined using tensile tests and are compared with literature. The tensile test results show that YS and UTS for flat-build samples have distinguishably higher values than those of the side-build and top-build samples.


Author(s):  
Mohammad-Reza Ashory ◽  
Farhad Talebi ◽  
Heydar R Ghadikolaei ◽  
Morad Karimpour

This study investigated the vibrational behaviour of a rotating two-blade propeller at different rotational speeds by using self-tracking laser Doppler vibrometry. Given that a self-tracking method necessitates the accurate adjustment of test setups to reduce measurement errors, a test table with sufficient rigidity was designed and built to enable the adjustment and repair of test components. The results of the self-tracking test on the rotating propeller indicated an increase in natural frequency and a decrease in the amplitude of normalized mode shapes as rotational speed increases. To assess the test results, a numerical model created in ABAQUS was used. The model parameters were tuned in such a way that the natural frequency and associated mode shapes were in good agreement with those derived using a hammer test on a stationary propeller. The mode shapes obtained from the hammer test and the numerical (ABAQUS) modelling were compared using the modal assurance criterion. The examination indicated a strong resemblance between the hammer test results and the numerical findings. Hence, the model can be employed to determine the other mechanical properties of two-blade propellers in test scenarios.


2014 ◽  
Vol 644-650 ◽  
pp. 381-384
Author(s):  
Xin Zhang ◽  
Hao Zhou ◽  
Guo Song Liu

In order to improve the efficiency of auto parts distribution logistics, to lower the cost of auto production in transportation logistics, and to reduce accidents, in this paper it is designed that an automatic guided vehicle control system to replace the manned tractors in the distribution sites. The system is equipped with an infrared homing device that can ensure the automated guided vehicle (AGV) along a predetermined route automatic driving at a given distribution information, without the needs to manually guided. Test results show that the circuit performance of AGV control system is stable to ensure the accuracy of the tracking in the practical application, and the mean absolute error of the tracking is less than 0.04m.


2014 ◽  
Author(s):  
M. Harbison ◽  
W. Koon ◽  
V. Smith ◽  
P. Haymon ◽  
D. Niole ◽  
...  

As a result of enhanced performance and mission requirements for Navy ships, ship design has dramatically increased the use of higher strength, lightweight steels and various local reinforcements, e.g., deck inserts, ring stiffeners, etc., in foundation designs to satisfy the design requirements for supporting machinery, consoles, and weapon systems among others. In additional to operational loading requirements, most of these foundations must also be designed to satisfy shock, vibration and other combat system requirements. While the same piece of equipment may be used in other ship contracts, the foundations are uniquely designed and require a separate analysis and drawing package. Computer modeling and Finite Element Analysis (FEA) have helped reduce the labor required to analyze foundations, but the high number of “unique” foundations as well as changes which necessitate a new analysis still create a large workload for engineers. This is further compounded by increased costs in production due to greater numbers of unique parts and materials that must be marked, stored, and retrieved later for fabrication. This goal of this project was to determine the cost-savings potential of leveraging past foundations work in designing, analyzing, and drawing foundations in the future. By the project’s conclusion Ingalls will have created a database for rapid access to previously-generated foundation information, the framework of which will be publicly available for all shipyards to populate with their own foundation information.


2014 ◽  
Vol 875-877 ◽  
pp. 1454-1457
Author(s):  
Pan Hu ◽  
Yi He Zhang ◽  
Feng Shan Zhou ◽  
Yue Wang ◽  
Meng Fu ◽  
...  

A novel anti-caking material (E-Oil) was prepared from waste animal/plant oil and triethanolamine by catalytic synthesis in this study. The E-Oil was analyzed by FTIR and the anti-caking effect of anti-caking materials was described by caking ratio. The FTIR results showed that the reaction product of Waste Animal/Plant Oil and Hydramine was surfactant with anti-caking effect. The anti-caking test results indicated that E-Oil made the caking ratio of compound fertilizer decrease from 39.75% to 16.33%. Taking the cost into consideration, the optimal fraction of E Oil was 5‰ and the caking ratio could reach 16.33%, which could approximately meet the application requirements.


2013 ◽  
Vol 765-767 ◽  
pp. 1507-1511
Author(s):  
Saeeda Sharmeen Rahman ◽  
Jing Nong Weng

This paper presents the Component-Based Software Engineering (CBSE) approach for usability testing of a web-site based on ISO 9241-11 usability guidance to achieve specified goals with effectiveness, efficiency and satisfaction. Usability testing is a technique used to evaluate a product by testing it on users. A particular type of website i.e. university web site was chosen and segmented in different components in modular forms according to the purpose of that component. Then component wise tasks as per ISO 9241-11 usability guidance were prepared to carry out the usability testing for evaluating the test web-site. After analyzing the results of component based usability testing, a proto-type version of the test web-site was designed in a limited form including all the feedback of test results. Finally, the proto-type web-site was re-evaluated for establishing the effectiveness of component based web usability method with the same tasks. The proposed component based usability testing method is expected to improve the design/content issues of web-site resulting the web-site much more user friendly, effective and less time and cost consuming.


Author(s):  
Denghong Xiao ◽  
Tian He ◽  
Xiandong Liu ◽  
Yingchun Shan

A novel approach of locating damage in welded joints is proposed based on acoustic emission (AE) beamforming, which is particularly applicable to complex plate-like structures. First, five AE sensors used to obtain AE signals generated from damage are distributed on the surface of the structure in a uniform line array. Then the beamforming method is adopted to detect the weld joints in the area of interest rather than all the points of the whole structure, and to determine the location and obtain information of AE sources. In order to study the ability of the proposed method more comprehensively, a rectangular steel tube with welded joints is taken for the pencil-lead-broken test. The localization results indicate that the proposed localization approach can effectively localize the failure welded joints. This improvement greatly reduces the cost of computation and also improves the efficiency of localization work compared with the traditional beamforming.


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