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1
Content available Experimental Analysis of the Load Capacity and Repeatability of Preloaded Bolted Joints
Szczęch Marcin, Horak Wojciech
Tribologia
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2020
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nr 4
71--77
EN
Bolted joints are among the most widespread and most important detachable connections used in mechanical engineering and construction. The common use of this connection group is reflected in the variety of types of screw connections. There are several geometric and material factors, and consequently tribological ones, that determine the load capacity and, which is often of key importance, the repeatability of the bolted joint. The paper presents a description of the test stand and the test results of preloaded bolted joints for different lubrication conditions. The measured parameters were the breaking force value of a double lap bolted joint and its repeatability and the axial force repeatability of the bolts tightened by an electronic torque wrench.
PL
Połączenia śrubowe to jedne z najbardziej rozpowszechnionych i najważniejszych rozłącznych połączeń pośrednich stosowanych w budowie maszyn i budownictwie. Powszechność zastosowania tej grupy połączeń ma swoje odzwierciedlenie w różnorodności typów połączeń skręcanych. Można wskazać na kilka czynników geometrycznych i materiałowych, a w konsekwencji tribologicznych, które determinują nośność złącza, i co w wielu przypadkach ma kluczowe znacznie, powtarzalność wykonania połączenia. W pracy przedstawiono opis stanowiska badawczego oraz wyniki badań złącz nakładowych sprężonych. Opracowane stanowisko umożliwia realizację kontroli momentu dokręcania nakrętki, siły napięcia wstępnego wytworzonego w śrubie oraz pomiar siły niszczącej złącze, z wykorzystaniem technik komputerowej akwizycji danych.
2
Content available Comparative studies of the seatings of propulsion plantsand auxiliary machinery on chocks made of metal and cast from resin. Part II. Mounting on cast resin chocks
Grudziński Paweł, Konowalski Konrad
Polish Maritime Research
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2020
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nr 1
126--133
EN
This article is Part II of the paper containing a description and results of the experimental studies of the deformations, friction processes and structural damping that occur in the foundation bolted joints of propulsion plant components and auxiliary machinery installed on sea-going ships. Part I of this research work presents an analysis of the rigid mountings of machines and devices to the foundations on steel or resin chocks, and explains the need to carry out relevant research in this area. It also presents the description and results of experimental studies carried out for a foundation bolted joint with a conventionally used steel chock. Part II (this article) contains a description and results of similar studies carried out for a foundation bolted joint with a modern chock – cast from epoxy resin compound (EPY), specially developed for this purpose. Then, a comparative analysis of the results obtained for both bolted joints in question was made and the foundation chocks of the poured-in-place resin compound were demonstrated to better fulfill their technical tasks than the steel chocks traditionally used for this purpose.
3
Content available Comparative studies of the seatings of propulsion plants and auxiliary machinery on chocks made of metal and cast of resin. Part I. Mounting on steel chocks
Grudziński Paweł, Konowalski Konrad
Polish Maritime Research
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2019
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nr 4
142--148
EN
This paper presents a description and the results of experimental studies of the deformation, friction and structural damping occurring in foundation bolted joints of propulsion plant components and auxiliary machinery that is rigidly mounted on sea-going ships. The rigid mounting of these devices to the ships’ structural foundations can be implemented in a traditional way, i.e. on chocks made of metal (usually of steel), or in a modern way, i.e. on chocks cast of resin, specially designed for this purpose. The main goal of this study is to perform a comparative analysis of these two solutions and to give a scientific explanation for why chocks cast of resin perform better in machinery seatings than the steel chocks traditionally used for this purpose. The paper consists of two parts. Part I presents the details of the rigid mountings of machinery to the foundations, and contains the results of experimental studies performed on a model of a foundation bolted joint with a traditional steel chock. Part II contains the results of similar studies carried out for a model of a bolted joint with a modern chock cast of resin. Next, a comparative analysis and evaluation of the results obtained for both investigated bolted joints was carried out, and conclusions were formulated to highlight important aspects of the problem from the point of view of science and engineering practice.
4
Content available Preload monitoring in a bolted joint using Lamb wave energy
Kędra R., Rucka M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2019
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Vol. 67, nr 6
1161--1169
EN
The knowledge of the load in prestressed bolted connections is essential for the proper operation and safety of engineering structures. Recently, bolted joints have become an area of intensive research associated with non-destructive diagnostics, in particular in the context of wave propagation techniques. In this paper, a novel procedure of bolt load estimation based on the energy of Lamb wave signals was proposed. Experimental tests were performed on a single lap joint of two steel plates. Ultrasonic waves were excited and registered by means of piezo-electric transducers, while precise measurement of the bolt load was obtained by means of using the force washer transducer. Experimental tests were supported by the finite element method analysis based on Schoenberg’s concept. The results showed that the relationship between the bolt load and signal energy was strongly nonlinear and it depended on the location of acquisition points.
5
Content available remote Effects of hole perpendicularity error on load distribution in single-lap double-bolt composite joints
Li R., Xiao R., Ge E., Gao H., Bao Y., Liu X.
Engineering Transactions
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2018
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Vol. 66, iss. 1
3--19
EN
Although automated machines are widely used in composite structure manufacturing, manually drilled holes are usually necessary due to spatial constrains and holes with perpendicularity errors are occasionally generated as a result. Considering the anisotropic properties of composite material, the influences of hole perpendicularity error on mechanical performances of composite joints are different from those of isotropic material. In this study, the effects of hole perpendicularity error on load distribution in single-lap double-bolt composite joints are discussed. A finite element model is first developed and verified both by analytical and experimental results. Parametric studies are then carried out taking into consideration bolt torque and hole perpendicularity error, represented by hole tilting direction and tilting angle. It is found that the hole tilting direction significantly affects on load distribution in composite joints. Although the loads taken by bolts are not significantly affected, it may make one composite plate take more than 60% of total loads. In addition, the influences of tilting angle on load distribution can be ignored in most cases, and as for the bolt torque, it is to enhance the influence of hole tilting direction.
6
Content available remote Effects of hole-perpendicularity error on joint stiffness of single-lap double-bolt composite joints
Liu X., Yang Y., Gao H., Bao Y., Li R., Chen L.
Engineering Transactions
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2017
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Vol. 65, iss. 2
289--305
EN
To investigate the influence of hole-perpendicularity error on stiffness of single-lap doublebolt composite joints, a finite element model was first created and validated by using the analogical mass-spring based model proposed by McCarthy et al. The model was then modified by introducing hole-perpendicularity error, with which the influences of hole-perpendicularity error, which is represented by hole-titling angle, hole-tilting direction, and bolt torque on the joint stiffness are studied. It is found that the hole-tilting direction causes the joint stiffness to either increase or decrease, which depends on the relation between the hole-tilting direction and the loading orientation. In addition, the hole-tilting angle strengthens the influence of hole-tilting direction and the bolt torque plays the most important role among the three factors in affecting the joint stiffness.
7
Content available The influence of applying supplementary web plates on structural joint moment resistance and rotational stifness
Urbańska-Galewska E., Deniziak P.
Structure and Environment
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2014
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Vol. 6, no. 2
11--17
PL
Continual trend to simplify structural elements and find less time-consuming solutions on construction site as well as inevitable increase in labour costs determine for instance elimination of those technological steps that are difficult to automation. Welding additional reinforcements and web stiffeners are great examples of such a step. The method presented in EN 1993-1-8 [8] is a result of long-term studies focused on calculating the moment resistance and stiffness of joints without transverse web stiffeners. Design calculations shown in this paper are based on resistance and stiffness growth analysis applying supplementary web plates. Authors consider validity of this solution due to construction effort and building durability remembering about minimization of the costs.
8
Content available Numeryczna i doświadczalna analiza propagacji fal sprężystych przez stalowe połączenie śrubowe
Rucka M., Kędra R.
Budownictwo i Architektura
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2014
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Vol. 13, nr 2
299--306
PL
W pracy przedstawiono numeryczną i doświadczalną analizę propagacji fal sprężystych w połączeniu śrubowym dwóch blach stalowych. Obliczenia numeryczne metodą elementów skończonych przeprowadzono dwuetapowo. W pierwszej fazie analizowano statyczny wpływ sił sprężających na stan odkształceń i naprężeń połączenia śrubowego, formułując warunki kontaktu zastosowane następnie w modelu dynamicznym. W analizie propagacji fal sprawdzono wpływ naprężeń wstępnych na rezultaty obliczeń. Porównawcze badania doświadczalne wykonano przy wykorzystaniu wzbudnika piezoelektrycznego oraz wibrometru laserowego.
EN
The paper presents experimental and numerical analysis of elastic waves propagation in bolted connection of two steel plates. Numerical calculations were carried out using finite element method in two stages. In the first stage, static behavior of the joint during bolts compression was analyzed. Results of static analysis were used to formulate contact conditions for dynamic models. The analysis of wave propagation was taken for four types of bolt connection model. Finally, experimental tests by using a laser vibrometer and piezoelectric actuator were made in order to validate finite element models.
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