Experimental Study on the Distribution of Temperature and Deformation in the Water Walls of an Opposed Firing Boiler under Variable Load Conditions

AbstractConnections made by self-drilling screws are often used in steel cold-formed structures and sheeting. Their structural properties, such as resistance, flexibility and ductility are obtained by testing under monotonically increasing loading and can influence on overall behaviour of structures. This paper presents results of experimental study how variable load deteriorates those structural properties of lap shear connections with self-drilling screws. One monotonic and four variable loading histories were utilized, with displacement and force control. Applied loading histories were aimed to simulate persistent design situation, which referred to the conditions of normal use according to EN 1990. Deterioration of resistance and flexibility have been assessed for each variable loading history. It was observed that resistance deterioration is directly proportional to loading range. In case of flexibility, at small displacement range connectors become stiffer. Degradation of flexibility starts to increase at larger displacement range.

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Automatic representation and detection of fault bearings in in-wheel motors under variable load conditions

Advanced Engineering Informatics ◽

10.1016/j.aei.2021.101321 ◽

2021 ◽

Vol 49 ◽

pp. 101321

Author(s):

Xian-Bo Wang ◽

Luqing Luo ◽

Lulu Tang ◽

Zhi-Xin Yang

Keyword(s):

Variable Load ◽

Load Conditions ◽

Automatic Representation

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An intelligent fault diagnosis method based on domain adaptation for rolling bearings under variable load conditions

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211032995 ◽

2021 ◽

pp. 095440622110329

Author(s):

Jianqun Zhang ◽

Qing Zhang ◽

Xianrong Qin ◽

Yuantao Sun

Keyword(s):

Feature Extraction ◽

Fault Diagnosis ◽

Domain Adaptation ◽

Rolling Bearing ◽

Training Data ◽

Variable Load ◽

K Nearest Neighbor ◽

Target Domain ◽

Bearing Faults ◽

Load Conditions

To identify rolling bearing faults under variable load conditions, a method named DISA-KNN is proposed in this paper, which is based on the strategy of feature extraction-domain adaptation-classification. To be specific, the time-domain and frequency-domain indicators are used for feature extraction. Discriminative and domain invariant subspace alignment (DISA) is used to minimize the data distributions’ discrepancies between the training data (source domain) and testing data (target domain). K-nearest neighbor (KNN) is applied to identify rolling bearing faults. DISA-KNN’s validation is proved by the experimental signal collected under different load conditions. The identification accuracies obtained by the DISA-KNN method are more than 90% on four datasets, including one dataset with 99.5% accuracy. The strength of the proposed method is further highlighted by comparisons with the other 8 methods. These results reveal that the proposed method is promising for the rolling bearing fault diagnosis in real rotating machinery.

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Methode zur Auslegung von Verzahnungskorrekturen unter Lastkollektivbelastung

Konstruktion ◽

10.37544/0720-5953-2019-09-76 ◽

2019 ◽

Vol 71 (09) ◽

pp. 76-81

Author(s):

Andreas Fingerle ◽

Michael Hein ◽

Thomas Tobie ◽

Michael Otto ◽

Karsten Stahl

Keyword(s):

Variable Load ◽

Eine Hohe ◽

Load Conditions

INHALT Die Notwendigkeit für Verzahnungskorrekturen im Hinblick auf die Flankentragfähigkeit ergibt sich in Leistungsgetrieben maßgeblich aus den lastbedingten Verformungen der umliegenden Bauteile sowie der Zahn- und Radkörperverformung selbst. Unter Lastkollektivbelastung sind auch diese Verformungen im Betrieb nicht konstant. In dieser Veröffentlichung wird ein Verfahren gezeigt, mit dem eine Flankenkorrektur ermittelt werden kann, die hinsichtlich der Flankentragfähigkeit unter Lastkollektivbelastung optimiert ist. Die gezeigte Methode wurde im Rahmen des FVA- Vorhabens 722/I entwickelt. Die Ergebnisse der Korrektur- bestimmung wurden anhand von Industriebeispielen validiert und weisen eine hohe Übereinstimmung mit den in der Praxis auf Basis von Erfahrungswissen ausgeführten Zahnflanken-korrekturen auf.   A Method to Determine Toothing Corrections under Variable Load Conditions

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Experimental study on vibration transmissibility of Pre-loaded XPE and PE packaging cushioning material

FME Transaction ◽

10.5937/fme2104962c ◽

2021 ◽

Vol 49 (4) ◽

pp. 962-968

Author(s):

Péter Csavajda ◽

Péter Böröcz

Keyword(s):

Experimental Study ◽

Static Load ◽

Damping Ratio ◽

Packaging System ◽

Static Loads ◽

Resonance Frequencies ◽

Vibration Transmissibility ◽

Protective Packaging ◽

Load Conditions ◽

Cushioning Material

Most of the shipped products are sensitive against shock and vibration events during the distribution. Various cushioning materials are usually used to prevent the product damages. During the design process the protective packaging system is developed by the engineers based on the cushion and vibration transmissibility features (ie. cushion curve) of the material used. However, after the assembly of the packaged-product, these are stored for various long periods in warehouse. During this time the products pre-load the cushioning material and its parameters can be changed. The main goal of this study is to evaluate the vibration transmissibility of PE and XPE cushioning material at varied storage (pre-loaded) time and static load conditions. Four different kinds of duration (1 hour, 10 hours, 100 hours and 1000 hours) were used for the pre-loading period at three different static loads (3.488 kPa, 4.651 kPa, and 6.976 kPa), and then at 0.5 oct/min sine sweep vibration the peak frequencies of response and vibration transmissibility, and damping ratio were determined. The results show that the effect of pre-loading is minimal by PE material, but can influence the resonance frequencies by XPE cushioning material. The findings of this study help the packaging engineers to understand better the mechanism of these cushioning materials and to design suitable protective packaging systems.

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