caa a22 4500 44536095X CHVBK 20180317142915.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s11071-010-9825-0 doi (NATIONALLICENCE)springer-10.1007/s11071-010-9825-0 Huang Bo-Wun Department of Mechanical Engineering, Cheng Shiu University, 840 Cheng Ching Rd. Niaosung, 833, Kaohsiung, Taiwan, ROC aut Instability of a cracked twisted beam with a time-dependent boundary [Elektronische Daten] [Bo-Wun Huang] The crack effect on the instability of a twisted beam with a time-dependent boundary, a drill in the drilling process, is studied in this work. This work presents the drilling force from the two active parts of a twisted drill subjected to small fluctuations during the drilling process. This small drilling force fluctuation may lead the system into a dynamically unstable condition. In this work, the instability of a drill with drilling force fluctuations is focused to study as the drill has a crack. A moving Winkler-type elastic foundation is used to approximate the drilling process and the multiple scale method is employed to solve for the unstable regions. Numerical analysis indicates that the unstable regions are enlarged and shifted to a lower frequency suddenly as a drill with a crack bites into a workpiece. It is also observed that the crack depth, thrust force and rotation speed drastically change the dynamic instability of the drilling process. Springer Science+Business Media B.V., 2010 Crack nationallicence Time-dependent boundary nationallicence Instability nationallicence Twisted beam nationallicence Nonlinear Dynamics Springer Netherlands 63/4(2011-03-01), 627-637 0924-090X 63:4<627 2011 63 11071 https://doi.org/10.1007/s11071-010-9825-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11071-010-9825-0 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Huang Bo-Wun Department of Mechanical Engineering, Cheng Shiu University, 840 Cheng Ching Rd. Niaosung, 833, Kaohsiung, Taiwan, ROC aut NATIONALLICENCE 773 0- Nonlinear Dynamics Springer Netherlands 63/4(2011-03-01), 627-637 0924-090X 63:4<627 2011 63 11071 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer