Static and dynamic behavior of steel-reinforced epoxy granite CNC lathe bed using finite element analysis

Abstract

Machine tools are used to manufacture components with desired size, shape, and surface finish. The accuracy of machining is influenced by stiffness, structural damping, and long-term dimensional stability of the machine tool structures. Components machined using such machines exhibit more dimensional variations because of the excessive vibration during machining at higher speeds. Compared to conventional materials like cast iron, stone-based polymer composites such as epoxy granite have been found to provide improved damping characteristics, by seven to ten folds, due to which they are being considered for machine tool structures as alternate materials. The stiffness of structures made of epoxy granite can be enhanced by reinforcing with structural steel. The current work highlights the design and analysis of different steel reinforcements in the lathe bed made of the epoxy granite composite to achieve equivalent stiffness to that of cast iron bed for improved static and dynamic performances of the CNC lathe. A finite element model of the existing the cast iron bed was developed to evaluate the static (torsional rigidity) and dynamic characteristics (natural frequency) and the results were validated using the experimental results. Then finite element models of five different steel reinforcement designs of the epoxy granite bed were developed, and their static and dynamic behaviors were compared with the cast iron bed through numerical simulation using finite element analysis. The proposed design (Design-5) of the epoxy granite bed is found to have an improvement in dynamic characteristics by 4–10% with improved stiffness and offers a mass reduction of 22% compared to the cast iron bed, hence it can be used for the manufacture of the CNC lathe bed and other machine tool structures for enhanced performance.

Thermal Investigations on a CNC Lathe Fitted with a Dynamically Enhanced Steel-Reinforced Epoxy Granite Bed

“…Chinnuraj et al [17], Venugopal et al [29] and [30] carried out investigations on the application of SREG structures to CNC lathe and VMC. Static and dynamic investigations have revealed that the use of SREG structures in machine tools will enhance the static and dynamic performance of the machine.…”

“…The objective of this work is to study the influence of the bi-material effect (different thermal properties) of steel and EG on the thermal behaviour of the lathe, in comparison to that of the lathe with the existing cast iron bed. In this work, investigations on the thermal behaviour of a CNC lathe built with an SREG bed have been carried out as a continuation of the static and dynamic investigations of this lathe presented by Chinnuraj et al [17]. The thermal error associated with SREG structures must be investigated in order to obtain the full benefits of the thermally inert, high damping tailor-made EG material.…”

“…EG structures are capable of replacing existing CI structures for bed and base applications; In such cases, it is critical to maintain the footprints of the traditional CI bed to meet assembly requirements. Metal reinforcements are an alternative to making significant form design changes to enhance static stiffness whilst also meeting footprint requirements [17]. Chinnuraj et al [17] presented the static and dynamic characteristics of a computerized numerical control (CNC) lathe with a CI bed and SREG bed.…”

“…Metal reinforcements are an alternative to making significant form design changes to enhance static stiffness whilst also meeting footprint requirements [17]. Chinnuraj et al [17] presented the static and dynamic characteristics of a computerized numerical control (CNC) lathe with a CI bed and SREG bed. Experiments revealed that the dynamic performance of the lathe with an SREG bed improved considerably compared to that of the lathe with a CI bed.…”

Dynamic Response Analysis of a Multiple Square Loops-String Dome under Seismic Excitation

“…Collapse of buildings during earthquakes causes serious casualties and economic losses. Much research has been carried out on recent years carried out by Chinese and foreign experts on the mechanical properties and stability of the string dome structure, such as seismic response and anti-seismic analysis [5][6][7][8], buckling and dynamic response under friction [9], model optimization design based on artificial neural networks [10], elastoplastic dynamic response [11], structural optimization algorithm and design [12][13][14], long-span discontinuous mechanical properties [15], initial geometric defect analysis [16], cable tension estimation [17], static and the dynamic analysis by finite element method [18,19], and thrust line analysis of masonry domes [20]. Gong, S.Y.…”