scholarly journals Predictivity of CNC Machine-Induced Vibrations on Inter-Story Floors Based on Coupled Experimental-Numerical Investigations

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 15
Author(s):  
Enrico Bergamo ◽  
Marco Fasan ◽  
Chiara Bedon

Machine-induced vibrations and their control represent, for several reasons, a crucial design issue for buildings, and especially for industrial facilities. A special attention is required, at the early design stage, for the structural and dynamic performance assessment of the load-bearing members, given that they should be optimally withstand potentially severe machinery operations. To this aim, however, the knowledge of the input vibration source is crucial. This paper investigates a case-study eyewear factory built in Italy during 2019 and characterized by various non-isolated computer numerical control (CNC) vertical machinery centers mounted on the inter-story floor. Accordingly, the structure started to suffer for pronounced resonance issues. Following the past experience, this paper reports on the efficiency of a coupled experimental-numerical method for generalized predictive and characterization studies. The advantage is that the machinery features are derived from on-site experiments on the equipment, as well as on the floor. The experimental outcomes are then assessed and integrated with the support of Finite Element (FE) numerical simulations, to explore the resonance performance of the floor. The predictability of marked resonance issues is thus analyzed, with respect to the reference performance indicators.

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 87 ◽  
Author(s):  
Enrico Bergamo ◽  
Marco Fasan ◽  
Chiara Bedon

Machine-induced vibrations represent, for several reasons, a crucial design issue for industrial buildings. At the early design stage, special attention is thus required for the static and dynamic performance assessment of the load-bearing members, given that they should optimally withstand ordinary design loads but also potentially severe machinery operations. The knowledge and reliable description of the input vibration source is a key step, similarly to a reliable description of the structural system, to verify. However, such a kind of detailing is often unavailable and results in a series of simplified calculation assumptions. In this paper, a case-study eyewear factory built in 2019 is investigated. Its layout takes the form of a two-story, two-span (2 × 14.6 m) precast concrete frame (poor customer/designer communication on the final equipment resulted in various non-isolated computer numerical control (CNC) vertical machines mounted on the inter-story floor, that started to suffer from pronounced resonance issues. Following past experience, this paper investigates the validity of a coupled experimental–numerical method that could be used for efficient assessment predictive studies. Based on on-site experiments with Micro Electro-Mechanical Systems (MEMS) accelerometers mounted on the floor and on the machine (spindle included), the most unfavorable machine-induced vibration sources and operational conditions are first characterized. The experimental outcomes are thus used to derive a synthetized signal that is integrated in efficient one-bay finite element (FE) numerical model of the floor, in which the machine–structure interaction can be taken into account. The predictability of marked resonance issues is thus emphasized, with a focus on potential and possible limits of FE methods characterized by an increasing level of detailing and computational cost.


2021 ◽  
Author(s):  
Paul M. Sobota

<p><br clear="none"/></p><p>During the optioneering phase, engineers face the challenge of choosing between myriads of possible designs, while, simultaneously, several sorts of constraints have to be considered. We show in a case study of a 380 m long viaduct how parametric modelling can facilitate the design process. The main challenge was to satisfy the constraints imposed by several different stakeholders. In order to identify sustainable, aesthetic, economic as well as structurally efficient options, we assessed several key performance indicators in real time. By automatically estimating steel and concrete volumes, a simple, yet suitable approximation of the embodied carbon (considering 85-95%) can be obtained at a very early design stage. In summary, our parametric approach allowed us to consider a wider range of parameters and to react more flexibly to changing conditions during the project.</p><p><br clear="none"/></p>


2010 ◽  
Vol 97-101 ◽  
pp. 3259-3262
Author(s):  
Lin Zhang ◽  
Wen He Liao ◽  
Hui Yang

A miniaturized CNC (Computerized Numerical Control) milling machining equipment was mentioned for micro milling processing. The equipment has a highest spindle speed of 90000rpm and the positioning accuracy of submicron. Furthermore, it described the design of CNC servo system of precision stage driven by linear motor. The servo experiments results verified the excellent static and dynamic performance of the system. The machining tests included a plane with a surface roughness of 215nm using a end milling cutter of Φ0.2μm, micro straight slots with a dimension error range of 1-2μm using a ball-end cutter of Φ0.2μm and some complex structures. The analysis results of these tests show that the system is able to fulfill the micro milling machining of micro components.


2010 ◽  
Vol 97-101 ◽  
pp. 2914-2920 ◽  
Author(s):  
Qin Wu ◽  
Zhi Yuan Rui ◽  
Jian Jun Yang

The computer numerical control (CNC) machine tool was investigated and the dynamics model for the servo feed system was established. Based on the fixing constraint of the ball screw, the mathematical models of axial stiffness and torsion stiffness are constructed. According to the effects of stiffness on the dynamic performance, the simulation model for CNC machine tool feed system with stiffness considered was set up by the dynamic simulation tool Simulink, and a curve representing the performance of the system was obtained. To reduce the effect of stiffness on the system, the feedforward control strategy is used for stiffness compensation. The simulation results show that the stability and response performances of the system are improved and the steady-state error of the system is reduced by the control strategy.


Author(s):  
Eliab Z. Opiyo

Numerous virtual and physical prototyping techniques have been developed in the past decades. These techniques are typically used for prototyping of products in the embodiment and detail design phases of the product development process, without taking into consideration the processes associated with products. These processes include sub-processes related to the operation of the products, interactivity of the product developer or the user with the product, and thinking and manipulative control of humans. The main challenge addressed in this paper is how to conceptualize and communicate ideas about products together with all accompanying processes. We have developed a new concept of abstract prototyping (AP), with the intent to enable the ideation and representation of products or systems as real life processes. In this paper, we present application case studies to demonstrate the applicability of this new concept of abstract prototyping. The preliminary results show that this is indeed the case and prove that process-focused abstract prototyping can be a useful new enabler for design communication. One of the major benefits of the proposed method over the competing approaches such as the application of VR solutions is that it provides a low-cost, but yet effective solution for the challenge of taking into consideration how the product will be used in user’s context or scenario at the very early design stage.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ying Wang ◽  
Xiangyu Wang ◽  
Jun Wang ◽  
Ping Yung ◽  
Guo Jun

Considering facilities management (FM) at the early design stage could potentially reduce the efforts for maintenance during the operational phase of facilities. Few efforts in construction industry have involved facility managers into the design phase. It was suggested that early adoption of facilities management will contribute to reducing the needs for major repairs and alternations that will otherwise occur at the operational phase. There should be an integrated data source providing information support for the building lifecycle. It is envisaged that Building Information Modelling (BIM) would fill the gap by acting as a visual model and a database throughout the building lifecycle. This paper develops a framework of how FM can be considered in design stage through BIM. Based on the framework, the paper explores how BIM will beneficially support FM in the design phase, such as space planning and energy analysis. A case study of using BIM to design facility managers’ travelling path in the maintenance process is presented. The results show that early adoption of FM in design stage with BIM can significantly reduce life cycle costs.


2013 ◽  
Vol 32 ◽  
pp. 112-124 ◽  
Author(s):  
Weilin Shen ◽  
Xiaoling Zhang ◽  
Geoffrey Qiping Shen ◽  
Terrence Fernando

2021 ◽  
Author(s):  
Venkat P. Nemani ◽  
Jinqiang Liu ◽  
Navaid Ahmed ◽  
Adam Cartwright ◽  
Gül E. Kremer ◽  
...  

Abstract Design for Remanufacturing (DfRem) is an attractive approach for sustainable product development. Evaluation of DfRem strategies, from both economic and environmental perspectives, at an early design stage can allow the designers to make informed decisions when choosing the best design option. Studying the long-term implications of a particular design scenario requires quantifying the benefits of remanufacturing for multiple life cycles while considering the reliability of the product. In addition to comparing designs on a one-to-one basis, we find that including reliability provides a different insight into comparing design strategies. We present a reliability-informed cost and energy analysis framework that accounts for product reliability for multiple remanufacturing cycles within a certain warranty policy. The variation of reuse rate over successive remanufacturing cycles is formulated using a branched power-law model which provides probabilistic scenarios of reusing or replacing with new units. To demonstrate the utility of this framework, we use the case study of a hydraulic manifold, which is a component of a transmission used in some agricultural equipment, and use real-world field reliability data to quantify the transmission’s reliability. Three design improvement changes are proposed for the manifold and we quantify the costs and energy consumption associated with each of the design changes for multiple remanufacturing cycles.


2011 ◽  
Vol 308-310 ◽  
pp. 579-583
Author(s):  
Jian Wen Chen ◽  
Lei Li ◽  
Jin Chun Song ◽  
Zhan Jun He

In CNC machine tools servo feed system, there are many uncertain parameters, it is difficult to establish accurate mathematical model of the Servo feed system. The parameters of conventional PID controller can’t adjust immediately to the controlled object. Fuzzy PID controller [1], which has the advantages of conventional PID control and fuzzy control, can solve these problems. We apply it in numerical control machine servo feed system. The simulation in MATLAB shows that the fuzzy auto-tuning PID controller improve the dynamic performance of the servo feed system and has better robustness.


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