Functional Products (FP) and Product Service Systems (PSS) may be seen as integrated systems comprising hardware and support services. For such offerings, availability is key. Little research has been done on integrating Data Stream Management Systems (DSMS) for monitoring (parts of) a FP to improve system availability. This paper introduces an approach for how data stream mining may be applied to monitor hardware being part of a Functional Product. The result shows that DSMS have the potential to significantly support continuous availability awareness of industrial systems, especially important when the supplier is to supply a function with certain availability.
In shipyard panel-production lines several rectangular plates ae butt welded to form large panels. One problem is the tendency of hot cracking in the end portion of the butt weld. In this paper transient temperature fields and stress fields in butt-welded plates are calculated using the finite-element method. The calculations are performed for different welding speeds, for different heat inputs, and for one-sided and two-sided welding.
Numerous head impact tests have been carried out by the Biomechanics department of the Highway Safety Research Institute, University of Michigan, Ann Arbor, during the past few years. The purpose of this work is to investigate the head motion during impact loading (the unloading phase is not considered) and especially to determine if the head slips on the impactor or rotates around it. Data from three different types of tests have been analyzed: Front, side and rear impacts on human heads. The data consists of linear and angular accelerations and velocities for the head (considered as a rigid body). These four quantities are some of the most common that have been suggested as primary causes of injury. By using experimental data the position of the instantaneous point of rotation was determined as a function of time during impact loading. It was found that slip occurs between the impactor and the head with very few exceptions. It was also found that the human skull performs plane motion after front or rear impact. This is probably due to the symmetry around the midsagittal plane. In side impact on the human skull it was found that the motion is three-dimensional.
In this paper we explore the opportunities of improving the testing and verification phases of product development in the automotive industry, through a combination of broadband telematic services and tools and methods for distributed collaborative engineering. The development of a prototype system for remote vehicle testing is described, and experiences from experimental usage of the system at an automotive winter testing facility are reported. The prototype system supports real time communication of audio, video and measurement data from a vehicle at a test track, to a remote location such as an automotive company's development site. Initial results from using the system are promising, indicating a clear potential of improving the testing and verification phases of product development within the automotive sector, which will be essential in the future in order to meet demands on shortened development cycles and increased testing needs.
In this paper we describe how controller area network (CAN) frames can be relayed over a wireless Internet connection, enabling remote access to the CAN buses of vehicles for applications in automotive telematics. This opens up many new possibilities for diagnostics, monitoring, testing, analysis and verification, which we believe can significantly reduce the time required for the testing and verification phases of automotive development. A CAN-over-IP tunneling protocol is described and the design and implementation of a generic system for remote access to the CAN bus of vehicles is presented. Examples of applications of the technology are given and implications in terms of new possibilities and challenges in automotive engineering are discussed.
Rapid advancement in information and communication technology in recent decades has presented new opportunities for carrying out sophisticated engineering work in distributed teams, using tools and techniques collectively referred to as Distributed Collaborative Engineering (DCE). This kind of on-line collaboration not only cuts costs due to reduced travel, but also fosters innovation in product development, by bringing together groups of people in collaborative teams with complementary competences, that would otherwise be difficult to realize. Moreover, the convergence of technologies for telecommunication and information technology now makes it possible for companies specialized in collaboration technology to deliver sophisticated services for DCE, which can be purchased by engineering companies on a pay-per-use basis. By outsourcing the installation, management and support of the collaboration tools, the engineering companies can focus on their product development projects while harnessing the full potential of DCE to become more efficient and competitive. We believe that this new way of conducting engineering work will be an important key to innovation in the future. In this paper, we analyze the requirements for delivering DCE as a service and describe the implications this has in terms of systems design, business models and competence requirements. Furthermore, in addition to the primary return on investment in DCE services, we cite cost reductions and reduced CO2 emissions as further benefits.
Simulation of automatic butt-welding of large plates was investigated. Two different steels were considered. The plates were tack-welded before the butt-welding. The simulation includes the tack-welding, the butt-welding and the cooling to room temperature. The simulations should lead to an understanding of the mechanics behind the change in gap width in front of the moving arc, which is of importance in automatic welding production. The residual stresses due to the butt-welding were also studied. The magnitude and the distribution of the residual stress are important in design of welded structures.
Many difficulties in welding result from the fact that heat input causes uneven heating of the welded object. This article reports on the results of an investigation carried out with the object to find out whether it is possible to predict residual stresses in welding and weld deformations with the aid of new computational methods used in continum mechanics. Butt welding of flat plates was studied in this investigation. Deformations, residual stresses, and gap width variations during the welding process were calculated.
In this paper root-bead welding of plates of two different sizes was experimentally and theoretically analysed. The material of the plates was a fine-grain steel with yield limit 360 MPa. The finite element method was used for both the thermal analyses and the mechanical analyses. Temperature-dependent material properties and volume changes due to phase transformations were considered. Plane stress conditions were assumed. Good agreement between calculated and measured values were obtained.
The influence of tack welding procedure on change in root opening was investigated. This change during the first part of welding depends on the order in which the tack welds are made. It is also affected by the starting position of the welding arc. These effects were studied in seven theoretical analyses - three cases where the tack welding procedures differed and four cases where the temperature fields at the beginning of the butt joint welding differed. The material investigated was a fine-grain steel with a yield stress of 360 MPa (52,200 psi) at room temperature. The filler material was ESAB 1. 2/12. 51 (AWS ER70S-6).
Many rotating machineries are supported by bearings with clearance, which are further clamped in, compared to the bearing stiffness, weak pedestals. As have been reported in several studies, it is essential to choose a proper clearance in order to avoid unwanted vibrations. When rotating machineries supported by bearings with clearance are subjected to stationary loads (gravity, magnetic pull etc.), it may not loose contact between the shaft and the bearing (i.e. full contact). However, even in full contact unwanted dynamics can occur which is of interest in this paper. It is found that the clearance give raise to anisotropic pedestal stiffness. It is further shown that some of the resonance frequencies decrease with the clearance.
The objective of the present study is to investigate the applicability of the Fourier transform technique to the analysis of vibrating damped beam structures. The practical use of the method is demonstrated by calculating a measure of the noise emitted by a vibrating damped beam. Different distributed Winkler-type foundations are studied as a means of noise reduction in the vibrating damped beam structure. This type of damping can be applied to the drill rods employed in rock drilling
Mathematical models of the cooling of large butt-welded plates are investigated. One thermoelastic infinite plate and one thermoelastic semi-infinite plate are considered. On the infinite plate two concentrated heat sources of constant power move with constant velocity along a straight line toward each other. They meet and are then immediately removed from the plate. On the semi-infinite plate one concentrated heat source of constant power moves with constant velocity along a straight line perpendicularly toward the edge and is removed as it reaches the plate edge. The straight plate boundary is thermally adiabatic and mechanically free. It is shown that after removal of the heat source(s) such tensile stresses remain much longer in the semi-infinite plate than in the infinite plate. The transverse tensile stresses may explain the tendency of hot cracking in the end portion of a butt-weld.
Some different thermomechanical models for the calculation of residual deformations and stresses in welding are discussed. Among the models are three-dimensional finite element models, shell element models, combined 3-D and shell element models, plane stress and plane deformation models. The usefulness and application of the different models are demonstrated. In all models the material is assumed to be thermoelastic plastic with temperature dependent thermal and mechanical material properties. Volume changes due to phase transformations are accounted for. Effects of transformation plasticity on the calculated residual stresses are included in the discussions. It is concluded that it is of utmost importance to chose the proper model for the welding situation at hand, as it is not possible to adopt fully three-dimensional models where it may be desirable. Welding of HY80 is given as an example
Transient analysis of a linear model of a bus was performed. In the experiment the right front wheel of the bus rolled over a bump and one acceleration, two axial forces in the wheel suspension and two bending moments in the frame of the bus were measured. The different parts of the bus were modeled by uniform Rayleigh-Timoshenko beams and rigid bodies. This beam element has a uniformly distributed stiffness, inertia and viscous and/or hysteretic damping along its axis. The loading of the bus due to the bump was in the theoretical analysis modeled by a prescribed transient displacement of the model of the wheel. The fast Fourier transform technique was utilized. Fairly good agreement between calculated and measured values was obtained.
Trends of more team working and cross-functional activities in Integrated Product Development increases the requirements on the computer-aided engineering technology used. Experience of using solid models in a product development project at Volvo Aero is presented. Further, it is described how thermal boundary conditions, calculated using Computational Fluid Dynamics simulations, can be integrated with thermal structural analysis in a commercial Finite Element code. It is argued that incremental technology development using technology based on international standards, e.g., the STEP standard, is a low-risk, highly efficient strategy for improving multi-functional analysis systems.
Collection and analysis of diagnostic data from electronic control units is of paramount importance in the automotive industry, both from a life cycle support perspective, and as a tool in the product development. For pre-series test vehicles, access to diagnostic data is crucial in order to be able to track problems as early as possible in the development process, preventing serious faults to pass undetected into production vehicles. However, systematic collection of diagnostic data from test vehicles is complicated by the fact that pre-series vehicles are frequently unavailable for diagnostic read-outs, while away on test expeditions in rural areas, or being operated by taxi companies, or being otherwise inaccessible. In response, we propose a system for wireless read-out of diagnostic data, based on an embedded system installed in the test vehicles and a server component at the automotive company. Moreover, we present a number of computer-based tools for statistical analysis of diagnostic trouble codes, to aid engineers in processing the potentially very large amount of diagnostic dataata generated by the automated collection system. We strongly believe that wireless diagnostic collection systems, in combination with statistical analysis tools, will be a key component in meeting future demands on reduced development time, while the complexity of automotive electronics continue to grow. Initial results from our pilot trials with the tools described in this paper support this claim.
Deformations and stresses during butt-welding of a pipe are calculated as well as the residual deformations and stresses. The temperature field during welding is calculated using an analytical solution. The deformations and stresses are calculated by use of the finite element method. A thermo-elastoplastic material model is used. Special attention is paid to the influence of the volume changes due to phase transformations on the deformations (radial shrinkage) and the residual stresses. The calculated radial shrinkage and residual stresses are compared to experimental values. Good agreement was obtained.
Four examples are used to illustrate the current ability to calculate residual stress and distortion in situations of varying complexity. The methodology used is capable of allowing for interactions between thermal, mechanical, and transformation processes. Experimental values for a 2.25Cr-1Mo ferritic stainless steel were used in the simulation. It seems possible to simulate most welding situations given sufficient computer resources
Engineering product development has developed considerably over the past decade. In order for industry to keep up with continuously changing requirements, it is necessary to develop new and innovative simulation methods. However, few tools and methods for simulation-driven design have been applied in industrial settings and proven to actually drive the development and selection of the ideal solution. Such tools, based on fundamental equations, are the focus of this paper. In this paper the work is based on two cases of mechanics of materials and structures: welding and rotor dynamical simulations. These two examples of simulation-driven design indicate that a larger design space can be explored and that more possible solutions can be evaluated. Therefore, the approach improves the probability of innovations and finding optimal solutions. A calibrated block dumping approach can be used to increase the efficiency of welding simulations when many simulations are required.