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Design and Experiments of an Origami-Inspired Pneumatic Flexible Manipulator

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Acta Mechanica Solida Sinica 2023年第2期36卷 254-261页

作者： Benzhu Guo Panding Wang Zeang Zhao Shengyu Duan Hongshuai Lei beijing key laboratory of lightweight multi-functional composite materials and structures Beijing Institute of TechnologyBeijing 100081China

Unlike traditional manipulators with high rigidity and limited degrees of freedom,pneumatic manipulators have significant superiorities such as flexibility,lightweight and cleanliness,and therefore,have been one of the most popular research directions in ***,most existing pneumatic manipulators have disadvantages such as low rigidity and simple *** order to make up for the shortcomings of existing pneumatic manipulators,this paper proposes a new pneumatic flexible manipulator inspired by the concept of origami,which realizes the combination and balance of flexibility and *** element analysis is conducted to study influences of the number of airbags,the angle of main beam,and the width of main beam on the performance of the flexible *** simulation results are utilized to optimize the structure of the flexible manipulator.A pneumatic control system is designed to realize the automatic control of the pneumatic flexible *** the same time,a prototype is 3D printed,the experimental platform for pneumatic deformation is built,and the verification experiments of the single-jaw manipulator and the three-jaw manipulator are completed.

关键词： Origami-inspired design Flexible structure Pneumatic drive Finite element analysis Pneumatic control system

Accuracy controlling and mechanical behaviors of precursor-derived ceramic SiOC microlattices by projection micro stereolithography(PμSL)3D printing

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Journal of Advanced Ceramics 2023年第11期12卷 2134-2147页

作者： Ruyue Su Jingyi Chen Xueqin Zhang Xiong Gao Wenqing Wang Ying Li Rujie He State key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China beijing key laboratory of lightweight multi-functional composite materials and structure Institute of Advanced Structure TechnologyBeijing Institute of TechnologyBeijing 100081China

Precursor-derived ceramic SiOC(PDC-SiOC)microlattices exhibit excellent oxidation resistance,high-temperature stability,and superior mechanical ***,the printing accuracy of the PDC-SiOC microlattices by 3D printing is still limited,and mechanical properties of the PDC-SiOC microlattices have not been studied ***,PDC-SiOC octet microlattices were fabricated by projection micro stereolithography(PμSL)3D printing,and photoabsorber(Sudan III)’s effect on the accuracy was systematically *** results showed that the addition of Sudan III improved the printing accuracy ***,the ceramization process of the green body was analyzed in *** order of the green body decreased,and most of their chemical bonds were broken during *** that,the PDC-SiOC microlattices with different truss diameters in the range of 52–220μm were fabricated,and their mechanical properties were *** PDC-SiOC microlattices with a truss diameter of 52μm exhibited higher compression strength(31 MPa)than those with bigger truss *** size effect among the PDC-SiOC microlattices was *** work provides a deeper insight into the manufacturing of PDC-SiOC micro-scaled architectures by 3D printing and paves a path to the research of the size effect in ceramic structures.

关键词： precursor-derived ceramic(PDC) microlattice projection micro stereolithography(PμSL) accuracy mechanical behaviors

Quantitative characterization of defects in stereolithographic additive manufactured ceramic using X-ray computed tomography

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Journal of materials Science & Technology 2022年第23期118卷 153-166页

作者： Keqiang Zhang Qiaoyu Meng Xueqin Zhang Zhaoliang Qu Rujie He Institute of Advanced structure Technology Beijing Institute of TechnologyBeijing 100081China beijing key laboratory of lightweight multi-functional composite materials and structures Beijing Institute of TechnologyBeijing 100081Chin

Ceramics have been widely fabricated by additive manufacturing(AM).Compared to conventional technologies,the strength of additive manufactured ceramic is relatively low owing to the formation of defects during manufacturing *** defects have significant effects on the microstructure and mechanical properties of additive manufactured ***,systematic research on defects,including defect geometrical features,quantitative statistics,and formation mechanism,as well as the intrinsic relationship with mechanical properties,need to be studied in *** this work,Al2 O3 ceramics were prepared from photosensitive slurries with different solid loadings by using stereolithographic(SL)additive *** defects,including their sizes and distributions,in both green and sintered bodies were investigated by using scanning electron microscopy(SEM)and X-ray computed tomography(X-CT).Geometrical features and quantitative statistics of the defects were evaluated and discussed to reveal their formation ***,the intrinsic relationship between defects and mechanical properties of the additive manufactured ceramic was *** study can give some fundamental understanding of the defects in additive manufactured ceramics.

关键词： Ceramic Stereolithographic additive manufacturing Defects X-CT Strength

A new method based on the shear lag model for accurate determination of ice adhesion shear strength on solid surface

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Science China(Technological Sciences) 2023年第4期66卷 987-997页

作者： HUANG JiaNan LI DaWei PENG ZhiLong ZHANG Bo YAO Yin CHEN ShaoHua Institute of Advanced structure Technology Beijing Institute of TechnologyBeijing 100081China beijing key laboratory of lightweight multi-functional composite materials and structures Beijing Institute of TechnologyBeijing 100081China

Accurate measurement of the interfacial shear strength between ice and solid surface has important reference significance for the design of anti-icing and de-icing functional *** this paper,a new method is proposed based on the shear lag model of a single fiber pulled out from matrix,in order to accurately determine the interfacial shear strength(ISS)between ice and *** maximum pull-out force at the initiation of interface debonding is well measured in the pull-out test of a metal fiber embedded in an ice matrix.A shear lag model similar to the pull-out test is established and a closed-form relation between the non-uniform interfacial shear stress and the pull-out force is *** the pull-out force reaches its peak value,the ice/metal ISS can be consequently determined as the maximum interfacial shear *** a method takes into account the stress concentration at the interface,which overcomes underestimation of ice/solid ISS based on the apparent strength in previous *** achieved ISS is proven to not only have good convergence,but also be independent of the size and embedded depth of metal *** on the present method,the enhancing effects of freezing temperature and surface roughness on the ice adhesion are further *** present research provides a simple and reliable approach to accurately calibrate the ice/solid ISS,which should be of important reference significance for the design and assessment of anti-icing functional surfaces.

关键词： ice adhesion pull-out test shear lag model interfacial shear strength(isS) stress concentration

The scaling laws of cabin structures subjected to internal blast loading:Experimental and numerical studies

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Defence Technology（防务技术） 2022年第5期18卷 811-822页

作者： Xian-ben Ren Zhi-xin Huang Yong-bo Jiang Zi-hao Chen Xiao-fei Cao Tian Zhao Ying Li beijing key laboratory of lightweight multi-functional composite materials and structures Institute of Advanced Structure TechnologyBeijing Institute of TechnologyBeijing100081China State key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

This paper presents a combination of experimental and numerical investigations on the dynamic response of scaling cabin structures under internal blast *** purpose of this study is to modify the similar relationship between the scaled-down model and the prototype of the cabin structures under internal blast *** to the Hopkinson’s scaling law,three sets of cabin structure models with different scaling factors combined with different explosive masses were designed for the experimental *** dynamic deformation process of the models was recorded by a three-dimensional digital imaging correlation(DIC)method and a 3D scanning technology was used to reconstruct the deformation modes of the *** addition,a finite element model was developed for the modification of the scaling *** experimental results showed that the final deflection-to-thickness ratio was increased with the increase of the model size despite of the similar trend of their deformation *** reason for this inconsistency was discussed based on the traditional scaling law and a modified formula considering of the effects of size and strain-rate was provided.

关键词： Internal blast Cabin structure Scaling law Experimental study Numerical simulation

Effective Impulse for Fully Clamped Rectangular Plates Under Internal Blast Loading

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Acta Mechanica Solida Sinica 2022年第3期35卷 481-494页

作者： Xianben Ren Xiaoqiang Zhang Zhixin Huang Ying Li State key laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China beijing key laboratory of lightweight multi-functional composite materials and structures Institute of Advanced Structure TechnologyBeijing Institute of TechnologyBeijing 100081China

Under internal blast loading,the response of a beam or plate is highly correlated with the phenomenon of saturated impulse,which governs the deflection of the *** paper aims to investigate the phenomenon of saturated impulse for fully clamped rectangular plates subjected to internal blast *** on the rigid,perfectly plastic assumption,the relationship between saturation duration and saturation deflection is *** of the peak shock wave,the duration of shock wave and the peak quasi-static pressure loading on saturation duration and saturation deflection are *** is found that there is a critical duration for the internal blast impulse to reach saturation,and beyond this duration,the deflection of plate will no longer increase as the loading increases *** saturation deflection and saturation duration both exhibit regular variation patterns with the changes of the dimensionless peak shock wave,the duration of shock wave and the peak quasi-static pressure loading.

关键词： Internal blast Effective impulse Rectangular plate Effective acting time Simplified model

Rapid heating thermal shock study of ultra high temperature ceramics using an in situ testing method

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Journal of Advanced Ceramics 2017年第4期6卷 279-287页

作者： Rujie HE Zhaoliang QU Dong LIANG Institute of Advanced structure Technology Beijing Institute of TechnologyBeijing 100081China beijing key laboratory of lightweight multi-functional composite materials and structures Beijing Institute of TechnologyBeijing 100081China

In this paper,the rapid cooling thermal shock behaviors of ZrB_(2)-SiC ceramics were measured using traditional water quenching method,and the rapid heating thermal shock behaviors of ZrB_(2)-SiC ceramics were investigated using a novel in situ testing *** measured critical thermal shock temperature difference for rapid cooling thermal shock was 373.6℃;however,the critical thermal shock temperature difference for rapid heating thermal shock of ZrB_(2)-SiC ceramics was measured to be as high as 1497.2℃.The thermal stress distribution states after rapid cooling thermal shock and rapid heating thermal shock testing were analyzed using finite element analysis(FEA)*** FEA results showed that there is a tensile stress existed on the surface for rapid cooling thermal shock,whereas there is a compressive stress existed on the surface for rapid heating thermal *** difference of thermal stress distribution resulted in the difference of the critical temperature difference for rapid cooling thermal shock and rapid heating thermal shock.

关键词： ultra high temperature ceramics(UHTCs) thermal shock behavior thermal stress finite element analysis(FEA)

Adaptive enhancement design of triply periodic minimal surface lattice structure based on non-uniform stress distribution

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Applied Mathematics and Mechanics(English Edition) 2023年第8期44卷 1317-1330页

作者： Yijin ZHANG Bin LIU Fei PENG Heran JIA Zeang ZHAO Shengyu DUAN Panding WANG Hongshuai LEI beijing key laboratory of lightweight multi-functional composite materials and structures Beijing Institute of TechnologyBeijing 100081China beijing Institute of Astronautical Systems Engineering Beijing 100076China

The Schwarz primitive triply periodic minimal surface(P-type TPMS)lattice structures are widely ***,these lattice structures have weak load-bearing capacity compared with other cellular *** this paper,an adaptive enhancement design method based on the non-uniform stress distribution in structures with uniform thickness is proposed to design the P-type TPMS lattice structures with higher mechanical *** types of structures are designed by adjusting the adaptive thickness distribution in the *** keeps the same relative density,and the other keeps the same of non-enhanced region *** with the uniform lattice structure,the elastic modulus for the structure with the same relative density increases by more than 17%,and the yield strength increases by more than 10.2%.Three kinds of TPMS lattice structures are fabricated by laser powder bed fusion(L-PBF)with 316L stainless steel to verify the proposed enhanced *** manufacture-induced geometric deviation between the as-design and as-printed models is measured by micro X-ray computed tomography(μ-CT)*** quasi-static compression experimental results of P-type TPMS lattice structures show that the reinforced structures have stronger elastic moduli,ultimate strengths,and energy absorption capabilities than the homogeneous P-TPMS lattice structure.

关键词： additive manufacturing(AM) triply periodic minimal surface(TPMS) enhanced design model mechanical property micro X-ray computed tomography(u-CT)

Influence of Spatial Correlation Function on Characteristics of Wideband Electromagnetic Wave Absorbers with Chaotic Surface

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Chinese Physics Letters 2022年第9期39卷 23-27页

作者： Rui Zhang Fan Ding Xujin Yuan Mingji Chen beijing key laboratory of lightweight multi-functional composite materials and structures Institute of Advanced Structure TechnologyBeijing Institute of TechnologyBeijing 100081China China Ship Development and Design Center Wuhan 430064China

Electromagnetic metasurface with chaos patterned surface could bring rich interaction modes contributing to fully disordered random motions in deterministic systems, which preform uncertainty, irreducibility and unpredictability. We investigate the influence of the correlation function(CF) properties of surface random patterns on the wave absorption performance. The complicated correlation function provides a fully developed random state, broadening the absorption bandwidth significantly and is helpful for reaching higher absorption rate. With the increasing number of peaks in the correlation function, the absorption band at-15 d B reflectivity widens significantly, band at-20 d B reflectivity begins to emerge. As the first peak’s distance from the original point in the CF is enlarged, the absorption trough is gradually formed and deepened to-35 d B level. The results give in-depth understanding of the relation between absorption behavior and controlling parameters including correlation, image information and foam spacer layer thickness. This high absorption absorber has great application potential in customizable radio communication compatibility device and anechoic testing chamber.

关键词： absorption Electromagnetic reflectivity