Klaus Hoffmann

Modelling of dynamic interaction between structure and trolley for mega container cranes

This article deals with the analysis of trolley impact on the dynamic behaviour of the flexible structure of the mega quayside container crane (QCC) boom, identified as the most relevant structural part. It develops a modelling method for the dynamic response of the large flexible structure of the QCC boom under a moving trolley. By using FEM the original structure of the whole crane structure is reduced to an equivalent model of the boom. The boom is in this way modelled as a system with distributed parameters, comprising reduced stiffnesses and lumped masses from other parts of the upper structure. The article looks at the moving mass approach to achieve the desired performance of the QCC. Differential equations of the mathematical model are obtained by using Lagranges equations and the assumed mode method. The continuum is discretized by a finite number of admissible functions. Deterministic simulation gives the dynamic response of the boom for quay-to-ship container transfer. Results are obtained for the boom deflection and bending moment values, as well as for the dynamic amplification factor of deflection.

Parameter sensitivity analysis of non-dimensional models of quayside container cranes

This paper gives an analysis of dynamic behaviour of the waterside boom, previously identified as the most important structural part of the mega quayside container cranes (QCC) under moving concentrated mass. The non-dimensional mathematical model used in this paper presents a conceptual substitution of the real system of the mega container crane boom and provides understanding and prediction of its dynamic behaviour under the action of a moving trolley. The paper discusses the procedure for setting up the nondimensional mathematical model of the crane boom as a necessary condition for an estimation of structural and trolley drive parameters, such as the effects of stiffness, mass, spatial position of structural segments as well as trolley velocity and acceleration, on the dynamic values of deflection under the moving mass. The results obtained by the simulation of the trolley motion alongside the QCC boom during container transfer from quay-to-ship are implemented in the parameter sensitivity analysis in order to obtain mutual influences of the dynamic parameters.

Inaccuracies in measurement of contact pressure due to the measuring grid of a foil sensor

The measurement of contact stresses between elastic bodies is of great importance in a wide range of fields. Many methods are based on a sensor sheet which is placed between the bodies in contact. Depending on the application, the accuracy of measuring results can be considerably affected by the finite thickness and structure of the inserted sensor. This study deals with the imprecision of the Tekscan system and attempts to explain the cause of deviations. For this purpose an imprint method using Fuji prescale film/GODAV software and the Finite Element (FE) method was used to compare the results with those results of the Tekscan system. As an example where high inaccuracies can be caused by the measuring grid of the Tekscan sensor, the pressure distribution in the contact area between the rope and the polyamide inlay of a pulley wheel was measured. The results demonstrate clearly the high influence of the sensor grid.

Development of Design of Ship-To-Shore Container Cranes: 1959–2004

The paper presents the historical development of mechanical and structural design of ship-to-shore (STS) container cranes, from 1959, when the first crane was built, up to now. The paper gives a short survey of the evolution of the container crane industry, the state of the art in modern container cranes, and focuses particular attention on mechanical design of trolleys and evaluation of the existing structures. The analysis of historical development and state of the art in modern container cranes enables us to analyze future trends in mechanical and structural design.

Modelling and simulation of bicable ropeways under cross-wind influence

Improvements of safety standards of ropeways are crucial in order to ensure a high level of operational reliability and safety. In this context, the question of cross-wind stability of ropeways is of particular concern. The real cross-inclination of the gondola and its correlation to wind speed and direction on an operating ropeway are of great interest for ropeway manufacturers and responsible authorities as well as for ropeway operators. As presented in this paper, a mathematical model for simulation was developed in order to gain a better understanding of the cross-wind behaviour of bicable ropeways. This model was established for a numerical dynamic simulation of the movement of gondolas with stiff connections, ‘hanger-cabins’, due to arbitrary cross-wind loads acting at a section of the studied span of the ropeway. All equations were solved using the program MATLAB® and the toolbox SIMULINK®. In addition, the results of a simulation of a real ropeway are presented.

Cable-Drawn Urban Transport Systems

Cable-drawn transport systems have been in use for a long time for passenger transportation, mostly in alpine areas. However, in recent years these transport systems have also been increasingly used in urban areas. In this paper the various structural forms of cable-drawn passenger transportation systems particularly suited for urban transportation solutions are discussed. Particular attention will focus on single- or bicable continuous ropeway systems, funicular railways in continuous or reversible operation and inclined lifts. The function and mode of operation as well as design of these cable railway systems will be described in detail. The possible incorporation in the urban traffic flow will be demonstrated with several of the solutions at present under construction or already in operation with quite diverse systems. Apart from the advantages and disadvantages, the summary will describe the current fields of application and operational limits of the individual types of construction regarding travel speed, route lengths and carrying capacity. For the covering abstract see ITRD E129315.