A novel compression-induced twisting(CIT)-compliant mechanism was designed based on the freedom and constraint topology(FACT)method and manufactured by means of laser powder bed fusion(LPBF).The effects of LPBF printi...A novel compression-induced twisting(CIT)-compliant mechanism was designed based on the freedom and constraint topology(FACT)method and manufactured by means of laser powder bed fusion(LPBF).The effects of LPBF printing parameters on the formability and compressive properties of the laserprinted CIT-compliant mechanism were studied.Within the range of optimized laser powers from 375 to 450 W and with the densification level of the samples maintained at above 98%,changes in the obtained relative densities of the LPBF-fabricated CIT-compliant mechanism with the applied laser powers were not apparent.Increased laser power led to the elimination of residual metallurgical pores within the inclined struts of the CIT mechanism.The highest dimensional accuracy of 0.2% and the lowest surface roughness of 20μm were achieved at a laser power of 450 W.The deformation behavior of the CIT-compliant mechanism fabricated by means of LPBF exhibited four typical stages:an elastic stage,a heterogeneous plastic deformation stage,a strength-destroying stage,and a deformation-destroying stage(or instable deformation stage).The accumulated compressive strain of the optimally printed CIT mechanism using a laser power of 450 W went up to 20% before fracturing,demonstrating a large deformation capacity.The twisting behavior and mechanical properties were investigated via a combination of finite-element simulation and experimental verification.An approximately linear relationship between the axial compressive strain and rotation angle was achieved before the strain reached 15% for the LPBF-processed CIT-compliant mechanism.展开更多
We study the buckling of a one fiber composite whose matrix stiffness is slightly dependent on the compressive force. We show that the equilibrium curves of the system exhibit a limit load when the induced stiffness p...We study the buckling of a one fiber composite whose matrix stiffness is slightly dependent on the compressive force. We show that the equilibrium curves of the system exhibit a limit load when the induced stiffness parameter gets bigger than a threshold. This limit load increases when the stiffness parameter is increasing and it is related to a possible localized path in the post-buckling domain. Such a change in the maximum load may be very desirable from a structural stand point.展开更多
基金supported by financial support from the National Natural Science Foundation of China(U1930207 and 51735005)the Basic Strengthening Program(2019-JCJQ-JJ-331)+3 种基金the 15th Batch of"Six Talents Peaks"Innovative Talents Team Program(TD-GDZB-001)National Natural Science Foundation of China for Creative Research Groups(51921003)National Natural Science Foundation of China(51905269)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘A novel compression-induced twisting(CIT)-compliant mechanism was designed based on the freedom and constraint topology(FACT)method and manufactured by means of laser powder bed fusion(LPBF).The effects of LPBF printing parameters on the formability and compressive properties of the laserprinted CIT-compliant mechanism were studied.Within the range of optimized laser powers from 375 to 450 W and with the densification level of the samples maintained at above 98%,changes in the obtained relative densities of the LPBF-fabricated CIT-compliant mechanism with the applied laser powers were not apparent.Increased laser power led to the elimination of residual metallurgical pores within the inclined struts of the CIT mechanism.The highest dimensional accuracy of 0.2% and the lowest surface roughness of 20μm were achieved at a laser power of 450 W.The deformation behavior of the CIT-compliant mechanism fabricated by means of LPBF exhibited four typical stages:an elastic stage,a heterogeneous plastic deformation stage,a strength-destroying stage,and a deformation-destroying stage(or instable deformation stage).The accumulated compressive strain of the optimally printed CIT mechanism using a laser power of 450 W went up to 20% before fracturing,demonstrating a large deformation capacity.The twisting behavior and mechanical properties were investigated via a combination of finite-element simulation and experimental verification.An approximately linear relationship between the axial compressive strain and rotation angle was achieved before the strain reached 15% for the LPBF-processed CIT-compliant mechanism.
文摘We study the buckling of a one fiber composite whose matrix stiffness is slightly dependent on the compressive force. We show that the equilibrium curves of the system exhibit a limit load when the induced stiffness parameter gets bigger than a threshold. This limit load increases when the stiffness parameter is increasing and it is related to a possible localized path in the post-buckling domain. Such a change in the maximum load may be very desirable from a structural stand point.
