This paper presents the development of a novel compliant polymorphing wing capable of chord and camber morphing for small UAVs.The morphing wing can achieve up to 10%chord extension and±20°camber changes.The...This paper presents the development of a novel compliant polymorphing wing capable of chord and camber morphing for small UAVs.The morphing wing can achieve up to 10%chord extension and±20°camber changes.The design,modeling,sizing,manufacturing and mechanical testing of the wing are detailed.The polymorphing wing consists of one continuous front spar fixed to the fuselage and a rear spar on each side of the wing.Each rear spar can translate in the chordwise direction(chord morphing)and rotate around itself(camber morphing).A flexible elastomeric latex sheet is used as the skin to cover the wing and maintain its aerodynamic shape whilst allowing morphing.The loads from the skin are transferred to the spars using the compliant cellular ribs that support the flexible skin and facilitate morphing.Pre-tensioning is applied to the skin to minimize wrinkling when subject to aerodynamic and actuation loads.A rack and pinion actuation system,powered by stepper motors,is used for morphing.Aero-structural design,analysis and sizing are conducted.Performance comparison between the polymorphing wing and the baseline wing(non-morphing)shows that chord morphing improves aerodynamic efficiency at low angles of attack while camber morphing improves efficiency at high angles of attack.展开更多
This paper presents the method for the performance calibration of AACMM （articulated arm coordinate measuring machines） according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has...This paper presents the method for the performance calibration of AACMM （articulated arm coordinate measuring machines） according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has been accompanied by an absence of authorized laboratories to provide calibration certificates for its performance. Due to ASME B89.4.22 and VD12617-9 are nowadays the unique standards in the field of AACMM verification, IK4 Tekniker has compared both of them in order to develop internal test procedures to yield reliable performance calibration results. As a result, IK4 Tekniker has been recognized by the Spanish Accreditation Body （ENAC） in the field of AACMM calibration. Internal test procedures and uncertainty evaluation analysis have been developed as well as ENAC certificated reference test equipments have been acquired to ensure a suitable AACMM calibration process.展开更多
The novel cast irons of chemical composition(wt%)0.7C-5W-5Mo-5V-10Cr-2.5Ti were invented with the additions of 1.6wt%B and 2.7wt%B.The aim of this work was to study the effect of boron on the structural state of the a...The novel cast irons of chemical composition(wt%)0.7C-5W-5Mo-5V-10Cr-2.5Ti were invented with the additions of 1.6wt%B and 2.7wt%B.The aim of this work was to study the effect of boron on the structural state of the alloys and phase elemental distribution with respect to the formation of wear-resistant structural constituents.It was found that the alloy containing 1.6wt%B was composed of three eutectics:(a)“M_(2)(C,B)_(5)+ferrite”having a“Chinese Script”morphology(89.8vol%),(b)“M_(7)(C,B)_(3)+Austenite”having a“Rosette”morphology,and(c)“M_(3)C+Austenite”having a“Ledeburite”-shaped morphology(2.7vol%).With 2.7wt%of boron content,the bulk hardness increased from HRC 31 to HRC 38.5.The primary carboborides M_(2)(C,B)_(5) with average microhardness of HV 2797 appeared in the structure with a volume fraction of 17.6vol%.The volume fraction of eutectics(a)and(b,c)decreased to 71.2vol%and 3.9vol%,respectively.The matrix was“ferrite/austenite”for 1.6wt%B and“ferrite/pearlite”for 2.7wt%B.Both cast irons contained compact precipitates of carbide(Ti,M)C and carboboride(Ti,M)(C,В)with a volume fraction of 7.3%-7.5%.Based on the energy-dispersive X-ray spectroscopy,the elemental phase distributions and the appropriate phase formulas are presented in this work.展开更多
基金support of Khalifa University of Science and Technology under Research Publication Award(Khan)with Project No.8474000195。
文摘This paper presents the development of a novel compliant polymorphing wing capable of chord and camber morphing for small UAVs.The morphing wing can achieve up to 10%chord extension and±20°camber changes.The design,modeling,sizing,manufacturing and mechanical testing of the wing are detailed.The polymorphing wing consists of one continuous front spar fixed to the fuselage and a rear spar on each side of the wing.Each rear spar can translate in the chordwise direction(chord morphing)and rotate around itself(camber morphing).A flexible elastomeric latex sheet is used as the skin to cover the wing and maintain its aerodynamic shape whilst allowing morphing.The loads from the skin are transferred to the spars using the compliant cellular ribs that support the flexible skin and facilitate morphing.Pre-tensioning is applied to the skin to minimize wrinkling when subject to aerodynamic and actuation loads.A rack and pinion actuation system,powered by stepper motors,is used for morphing.Aero-structural design,analysis and sizing are conducted.Performance comparison between the polymorphing wing and the baseline wing(non-morphing)shows that chord morphing improves aerodynamic efficiency at low angles of attack while camber morphing improves efficiency at high angles of attack.
文摘This paper presents the method for the performance calibration of AACMM （articulated arm coordinate measuring machines） according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has been accompanied by an absence of authorized laboratories to provide calibration certificates for its performance. Due to ASME B89.4.22 and VD12617-9 are nowadays the unique standards in the field of AACMM verification, IK4 Tekniker has compared both of them in order to develop internal test procedures to yield reliable performance calibration results. As a result, IK4 Tekniker has been recognized by the Spanish Accreditation Body （ENAC） in the field of AACMM calibration. Internal test procedures and uncertainty evaluation analysis have been developed as well as ENAC certificated reference test equipments have been acquired to ensure a suitable AACMM calibration process.
基金This work was financially supported by Ministry of Edu-cation and Science of Ukraine under the project No 0119U100080.
文摘The novel cast irons of chemical composition(wt%)0.7C-5W-5Mo-5V-10Cr-2.5Ti were invented with the additions of 1.6wt%B and 2.7wt%B.The aim of this work was to study the effect of boron on the structural state of the alloys and phase elemental distribution with respect to the formation of wear-resistant structural constituents.It was found that the alloy containing 1.6wt%B was composed of three eutectics:(a)“M_(2)(C,B)_(5)+ferrite”having a“Chinese Script”morphology(89.8vol%),(b)“M_(7)(C,B)_(3)+Austenite”having a“Rosette”morphology,and(c)“M_(3)C+Austenite”having a“Ledeburite”-shaped morphology(2.7vol%).With 2.7wt%of boron content,the bulk hardness increased from HRC 31 to HRC 38.5.The primary carboborides M_(2)(C,B)_(5) with average microhardness of HV 2797 appeared in the structure with a volume fraction of 17.6vol%.The volume fraction of eutectics(a)and(b,c)decreased to 71.2vol%and 3.9vol%,respectively.The matrix was“ferrite/austenite”for 1.6wt%B and“ferrite/pearlite”for 2.7wt%B.Both cast irons contained compact precipitates of carbide(Ti,M)C and carboboride(Ti,M)(C,В)with a volume fraction of 7.3%-7.5%.Based on the energy-dispersive X-ray spectroscopy,the elemental phase distributions and the appropriate phase formulas are presented in this work.
