 Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 CAE Analysis of Secondary Shaft Systems in Great Five-axis Turning-Milling Complex CNC Machine Chih-Chiang Hong 1,* , Cheng-Long Chang 1 , Chun-Chen Huang 2 , Chi-Ching Yang 3 , Chien-Yu Lin 4 1 Department of Mechanical Engineering, Hsiuping University of Science and Technology , Taichung, Taiwan, ROC. 2 Department of Industrial Engineering and Management , Hsiuping University of Science and Technology , Taichung, Taiwan, ROC. 3 Department of Electrical Engineering, Hsiuping University of Science and Technology, Taichung, Taiwan, ROC. 4 L&L Machinery Industry Co., Ltd, Taichung, Taiwan, ROC. Received 12 February 2017; received in revised form 12 April 2017; accept ed 23 April 2017 Abstract The commerc ial co mputer a ided engineering (CA E) software is used to analy ze the linear-static construction, stress and deformation fo r the secondary shaft systems in great five -a xis turning-milling co mple x co mputer numerical control (CNC) mach ine. It is convenient and always only three dimensional (3D) graphic parts needed firstly prepared and further mo re detail used for the co mme rcia l CA E. It is desirable to predict a defo rmed position for the cut tool under externa l pressure loads in the working process of CNC machine. The linear results for static analysis of stresses, displacements in corresponding to the screw shaft locates at top, mediu m and bottom positions of the secondary shaft systems are obtained by using the simulation module of SOLIDWORKS® . Keywor ds : CAE, static analysis , linear analysis , SOLIDWORKS, shaft systems, stress analysis, CNC 1. Introduction There are many co mputer a ided engineering (CA E) co mmerc ia l software used to develop and design the computer numerical control (CNC) machine for saving the cost of production. In 2016, Afkha mifar et al. [1] used the finite e le ment method (FEM) analysis to s imu late the position error of the tooltip in the 3-a xis vertical milling machin ing centers CNC series. In 2015, Ma x et al. [2] used CATIA® and NX™ software to create 3D models for the teaching and studies of FEM analysis in the CNC milling machine. In 2014, Altintas et a l. [3] simu lated and optimized the cutting process in the virtual machining (VM ) of CNC system. In 2014, Soori et al. [4] developed a VM software and created machined parts in the virtual environ ments for 3-a xis CNC. In 2013, Chang [5] introduced computer-based technology in the VM to provide a relative ly low setup cost when compared with physical CNC. In 2012, Wang et al. [6] used software ANSYS® (one of the FEM codes) to co mpute the static-structural results of the fra me and tool ca rrier fo r the hydraulic swing-type plate shears of CNC equip ments. There are also some other comme rcia l CA E software used in the structural analysis for the engineering system, for e xa mp le: SOLIDW ORKS® , Creo® , Inventor® , FreeCA D (an open -source), Abaqus® , HyperSize r® and midas® etc.. In 2016, MacKrell [7] introduced the mu lti-mechanics module o f software Abaqus® for engineer used to work and design in the fie ld of CA E. In 2013, Paulo et a l. [8] used software Abaqus® to simulate mechanica l behavior for the stiffened a lu minu m panels. In 2010, Youn is [9] presented the Autodesk software Inventor® used for the structural simulat ion in the engineering. To e xecute the fourth industrial revolut ion for the CNC systems, the design and analysis experiences of CA E are novel for the conventional company. In 2016, Hong et al. [10] presented the static -structural CA E analysis of great five-a xis turning-milling comple x machine for the CNC system with the SOLIDWORKS® simu lation module . Simp le, c lear and easy steps in the simu lated process are the specific reason of selecting SOLIDWORKS software for present work. Educational version of * Corresponding author. E-mail address: cchong@mail.hust.edu.tw Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI 44 SOLIDW ORKS 2014 software has been used for conducting the present simulation. In this paper, the linear static stresses and displacements of secondary s haft system of the CNC machines are studied more details and obtained with the SOLIDW ORKS® simulat ion module. The ma ximu m values of stress and displacement are usually provided to give a basic data for the detail construction of CNC machine. The highlight notes of this paper are also included as follows: (1) It is helpful for engineers to investigate great five-a xis turning-milling co mple x CNC machine data under CA E ana lysis . (2) Co mmerc ial CA E solution for the secondary shaft systems under e xternal pressure loads is provided. (3) The linear results are provided by using the simu lation module of SOLIDWORKS® . For the meaning of "great five-a xis " in this study usually notes that bigger dimensions of work piece e.g. length 5000 mm, dia meter 950 mm than s ma lle r one can be mach ined at working t ime by the five a xes: X-a xis, Y-a xis, Z -a xis (three translations), A-a xis and B-a xis (two rotations) of wor king platform wh ich moving respectively to the cutting tools . In 2015, Yang et a l. [11] presented the general stiffness model of rigidity for tool path planning in five-a xis CNC machin ing to restrain the chatter of the mach ine. In 2015, Wagner [12] p resented an optimization co mputer aided design (CAD)/co mputer aided manufacture(CAM)/ CA E technique for the processing of cutting tool of the comple x 3D s urfaces on 5 a xes CNC machines . The main novelty of their research is used the commerc ia l CA E simu lation module to investigate the linearly static structure analysis in CNC mach ine for t ime saving and obtain the basic data for the construction of CNC machine parts . In general, the using of commerc ia l CA E software have the trustable and acceptable experience in t he data, but the cost of module software is respectively higher when co mpared with personal developed software. Usually the c ommerc ial CAE software e.g. SOLIDWORKS® used for the educational version has the great discount in the universities and schools. T he ma in scope of this research is to use the reasonable cost of commerc ial CA E software to save developing time of software and find the useful data of co mputation. There a re so me c o mme rc ial CA E softwares in educational version had by the university e.g. CATIA® , A NSYS® and SOLIDWORKS® . They are all very good commerc ia l CAE softwares to provide the calculation solution. When the commerc ia l CA E software had for the industry is usually very e xpensive and needed some teaching courses to provide for the user. To choose which type of co mmerc ial CA E software is very important based on the user’s like of industrial company when the researcher and teacher of university are in the corporation relationship. The advantages of this paper in co mparison with the other researches performed in this subject are the using SOLIDWORKS® simu lation module is also used by the employee of industrial co mpany, the upgrading of new CNC machine design performed by the owners of industrial company and the reliable data calculated from the commercial CAE software. 2. Method The steps of simu lation with the software SOLIDWORKS® simu lation module in the static structural linear analysis and the general matrix equation of mathe matica l model were used in the computer program to solve for stress and displacement results by Hong et al. [10] as follows.     fuK  (1) where [K ] is materia l stiffness matrix, {u} is displace ment vector, {f} is e xternal load vector. It is necessary to prepare the assembling 3D parts of the secondary shaft systems as shown in Fig. 1. The dimensions of ma in parts are provided for the secondary shaft system is 1397mm 845mm 1426mm. The main co mponents of secondary shaft system are screw shaft and base. The tool is fixed on the end of scre w shaft to provide dril ling and milling functions. The secondary shaft system can be rotated by the base in rotational motion with respect to Y a xis. It is necessary to define the individual materia l of assembl ing 3D parts for the secondary shaft systems. The ma in materia ls of t he secondary shaft system are cast steel. The yie ld stress of cast steel material is 241MPa. To present normal working in the CNC machine, the value of working stress in each materia l of components should under its yield stress value. Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI 45 Three contact boundary conditions (B. C.) of secondary shaft systems are used to computed and analyzed for corresponding to the screw shaft locates at top, mediu m and bottom positions with 100mm apart along Y a xis, respectively. The boundary conditions of the secondary shaft s ystem for the base are four sides in clamp B.C. and shown in Fig . 2. External pressure loads on left-end of screw shaft and hydraulic pressure loads on the base in secondary shaft system for the screw shaft locates at top position typically is also shown. Mesh of grids in the secondary shaft system is shown in Fig . 3 and Fig. 4. Mesh of grids with para meter e le ment length equal to 27.21mm based on curvature mesh is shown in Fig . 3, also with proper mesh controlled base on the size of parts, mediu m mesh dens ity and used to generate a proper mesh of grids in the computation and analyses. A typical mesh of g rids in secondary shaft system for the screw shaft locates at top position is sh own in Fig. 4. A table is provided to define the characteristics of materials used in the simulation as shown in Table 1. Fig. 1 Assembling 3D parts of the secondary shaft system (a) Contact B.C. for the screw shaft locates at top position (b) Contact B.C. for the screw shaft locates at medium position (c) Contact B.C. for the screw shaft locates at bottom position (d) Four sides in clamp B.C. for the base Fig. 2 Boundary conditions in the secondary shaft system External pressure loads on left-end of screw shaft and hydraulic pressure loads on the base in secondary shaft system for the screw shaft locates at top position typically is also shown. Mesh of grids in the secondary shaft system is shown in Fig . 3 and Fig. 4. Mesh of grids with para meter e le ment length equal to 27.21mm based on curvature mesh is s hown in Fig. 3, also with proper mesh controlled base on the size of parts, mediu m mesh density and used to generate a proper mesh of grids in the computation and analyses. A typical mesh of g rids in secondary shaft system for the screw shaft locates at to p position is shown in Fig. 4. A table is provided to define the characteristics of materials used in the simulation as shown in Table 1. Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI 46 Table 1 Characteristics of materials Component Material Dimensions Yield stress Screw shaft Carbon steel 1397mm 220MPa ψ303mm Base Cast steel 1042mm 241MPa 815mm 231mm Sliding box 1 1023 Carbon steel 600mm 282MPa 540mm 350mm Sliding box 2 Carbon steel 600mm 220MPa 540mm 350mm Fig. 3 Mesh of grids parameters in the secondary shaft system Fig. 4 Typical grids in the secondary shaft system 3. Results and Discussion Firstly, used the SOLIDW ORKS® simu lation module to obtain the stresses and displacements of static results due to e xternal pressure loads (10MPa perpendicula r to XY plane, para lle l to X a xis and Y a xis, respectively) on left -end of the screw shaft and hydraulic p ressure loads (10MPa on the base) of secondary shaft system. The e xte rnal loads and their positions are determined in Table 2. Static stress and displacement results of secondary shaft system fo r screw shaft locates at top position are shown in Fig. 5 and Fig. 6, respectively. The ma ximu m value 131M Pa of stresses is found in the area of base and the ma ximu m value 0.522mm of displace ments is found in the top are a of secondary shaft system. The ma ximu m va lue (131MPa) of stress due to external pressure loads (10MPa in X, Y and Z) and hydraulic pressure loads (10MPa ) are less than yield stres s value 241MPa , so the parts of machinery are in safety condition. It suggests that the machinery of secondary shaft system can stand 10MPa e xterna l loads. A linear analysis is considered and clarified that the behavior of structure is also linear in fact, for the ma ximu m value 0.522mm o f displace ments found in the top area of secondary shaft system is very much less than the dimension length 1397mm of the screw shaft. Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI 47 Table 2 External loads and their positions External load Position Value Direction External pressure loads On left-end of the Screw shaft 10MPa Perpendicular to XY plane External pressure loads On left-end of the Screw shaft 10MPa Parallel to X axis External pressure loads On left-end of the Screw shaft 10MPa Parallel to Y axis Hydraulic pressure loads On top of the Base 10MPa Parallel to Y axis Fig. 5 Stress for the screw shaft locates at top position Fig. 6 Displacement for the screw shaft locates at top position Fig. 7 Stress for the screw shaft locates at top position Fig. 8 Displace ment for the screw shaft locates at top position Secondly, the simplic ity stresses due to the same e xternal p ressure loads (10M Pa) place on left -end of screw shaft are studied, when the screw shaft locates at top, mediu m and bottom position s of the secondary shaft system, respectively. Static stress and displacement results for the screw shaft locates at top position are shown in Fig. 7 and Fig. 8, respectively . Fig. 9 Stress for the screw shaft locates at medium position Fig. 10 Displacement for the screw shaft locates at medium position Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI 48 The ma ximu m value 64M Pa of stresses is found in the area of base and the ma ximu m va lue 0.1012 mm of displace ments is found in the left-end area of screw shaft and in the left-top-end area of fra me. Static stress and displacement results for the screw shaft locates at mediu m position are shown in Fig . 9 and Fig. 10, respectively. The ma ximu m va lue 61MPa of stresses is found in the area of base and the ma ximu m va lue 0.0864 mm of displace ments is foun d in the left-end area of screw shaft. Static stress and displacement results for the screw shaft locates at bottom position are shown in Fig . 11 and Fig. 12, respectively. The ma ximu m value 67MPa of stresses is found in the area of base and the ma ximu m va lue 0.07839mm of displacements is found in the left-end area of screw shaft. The ma ximu m va lue (0.1012mm) of d isplacement due to static-uniform pressure external loads (10MPa) can be occurred at the left -end area of screw shaft, so the cut tool deflection in the secondary shaft system should be reconsidered for the accuracy operation and safety condition . Fig. 11 Stress for the screw shaft locates at bottom position Fig. 12 Displacement for the screw shaft locates at bottom position Fig. 13 Stress for the screw shaft Fig. 14 Displacement for the screw shaft Fig. 15 Stress for the sliding box 1 Fig. 16 Displacement for the sliding box 1 Thirdly, the screw shaft in the detail studies are investigated due to the same e xternal pressure loads (10MPa perpendicular to XY p lane, paralle l to X a xis and Y a xis, respectively) on left -end of the screw shaft. Static stress and displacement results for the screw shaft are shown in Fig . 13 and Fig. 14, respectively. The ma ximu m value 65M Pa of stresses is found in the corner area of shaft and the ma ximu m va lue 0.058mm o f displace ments is found in the left -end a rea of the screw Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI 49 shaft. The sliding bo x in the detail studies are investigated due to the s ame e xternal pressure loads (10MPa downward to Z a xis) on the one-end-side of slid ing bo x. Static stress and displacement results for the sliding bo x 1 material are shown in Fig . 15 and Fig. 16, respectively. Fig. 17 Stress for the sliding box 2 Fig. 18 Displacement for the sliding box 2 The ma ximu m value 309M Pa of stresses is found in the sliding -groove area of bo x and the ma ximu m va lue 0.046 mm of displacements is found in the front-central area of the sliding bo x. The ma ximu m value (309M Pa) of stress due to external pressure loads (10MPa downwa rd to Z a xis) is g reater than yie ld stress value 282M Pa, so the sliding bo x of machinery is in un-safety condition. It suggests that the machinery of the slid ing box 1 materia l can't e xceed 10MPa e xte rnal loads. It is more interesting to observe some places/spots where there are some stress concentrations that will occur due to different material properties. Static stress and displacement results for the slid ing box 2 materia l are shown in Fig. 17 and Fig. 18, respectively. The ma ximu m value 2126MPa of stresses is found in the sliding -groove area of bo x and the ma ximu m value 0.05221 mm of displacements is found in the front-central area of the sliding box. The ma ximu m value (2126MPa ) of stress due to extern al pressure loads (10M Pa downwa rd to Z a xis) is much greater than yield stress value 220MPa (a lmost 10 times), so the sliding box of machinery is in un-safety condition. In the linear analysis, it suggests that the machinery of the slid ing bo x 2 material can't exceed 1M Pa e xterna l loads. More informat ive with further analysis related to this study would be the cut position on th e screw shaft in the milling process simulation subject. It would be interesting to investigate the optimize variable pitch fo r the cut under the milling and turning processes with considering the effects of stress and displacement . 4. Conclusions In this paper, the static linear stress and displacements of secondary shaft system under e xte rnal pressure loads in CNC mach ines are obtained with the simu lation module of SOLIDWORKS® . Under the action values of externa l pressure loads 10M Pa and hydraulic pressure loads 10MPa , when the screw shaft locates at top position, the ma ximu m va lue 131MPa of stresses is found in the area of base and the ma ximu m value 0.522mm o f d isplacements is found in the top area of secondary shaft system. The ma ximu m values of stress and displacement are usually provided to give a basic data for the detail and good construction of secondary shaft system, so the CNC machine can present in normal working condition . Acknowledgement The completion of this paper was enabled by a grant 105-IEM-1244 from Hsiuping University of Science and Technology, Taiwan, ROC. References [1] A. Afkhamifar, D. Antonelli, and P. Chiabert, “Variational analysis for CNC milling process,” Procedia CIRP, vol. 43, pp. 118-123, 2016. Advances in Technology Innovation, vol. 3, no. 1, 2018, pp. 43 - 50 Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI Cop y right © TAETI 50 [2] A. Max, V. Lašová, and Š. Pušman, “Enhancement of teaching design of CNC milling machines,” Procedia - Social and Behavioral Sciences, vol. 176, pp. 571-577, 2015. [3] Y. Altintas, P. Kersting, D. Biermann, E. Budak, B. Denkena, and I. La zoglu, “Virtual process systems for part machining operations,” CIRP Annals - Manufacturing Technology, vol. 63, no. 2, pp. 585-605, 2014. [4] M. Soori, B. Arezoo, and M. 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