共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
在当前反恐战争和地区武装冲突迫切形势下,如何提高车辆及人员的防护能力是诸多学科工作者面临的共同挑战。综述了威胁车辆安全的常见爆炸物、其作用原理和影响爆炸物作用载荷的因素,阐述了爆炸物爆炸冲击对车辆的破坏和人员损伤的各类不同形式。在此基础上分析了相关的实验、表征和模拟技术的研究进展,总结了国内外车辆爆炸防护结构的研究现状,包括轻质防护材料和结构的研发趋势,展望了车辆爆炸防护结构设计的研究趋势。 相似文献
4.
5.
《应用力学学报》2021,(3)
基于ABAQUS/Explicit建立了GLARE的有限元模型,分析了其在低速冲击载荷作用下的动态响应,讨论了低速冲击过程中冲头与层合板之间的接触力随冲头位移的变化过程,并进一步分析了低速过程中结构的破坏过程及能量平衡。研究发现:冲头承受的载荷在冲击过程中会发生剧烈变化,且在击穿GLARE前,载荷受冲击速度影响很小;冲头的动能损失基本转化成了层合板结构增加的内能,主要包括铝合金板的塑性变形能、整体材料应变能、因损伤破坏吸收的能量;其中铝合金板的塑性变形能占比最高,可通过进一步设计铝合金板来提高GLARE的抗冲击性能。本文为GLARE层合板在结构冲击防护中的设计及应用提供了重要的参考依据。 相似文献
6.
7.
用动态焦散线方法研究圆环在冲击载荷作用下的破坏机理 总被引:1,自引:0,他引:1
本文用动态焦散线实验方法并结合理论分析,深入地研究了圆环在冲击载荷作用下的破坏问题。考察了试件的几何尺寸和支承材料对破坏模态及破坏过程的影响。用应力波传播的几何理论(rays-theory)分析了应力波在圆环内部的传播过程,着重分析了圆环中应力波聚焦的现象。理论分析和实验结果在破坏时刻和破坏位置上吻合的很好。 相似文献
8.
9.
10.
11.
Dr.-Ing. W. Pechau 《Archive of Applied Mechanics (Ingenieur Archiv)》1963,32(3):157-186
Ohne ZusammenfassungAus dem Institut für Strömungsmechanik der Technischen Hochschule Braunschweig (Leiter: Prof. Dr.H. Schlichting). Gekürzte Fassung der von der Fakultät für Maschinenwesen der Technischen Hochschule Braunschweig genehmigten Dissertation 1962. Berichter: Prof. Dr.H. Schlichting; Mitberichter: Prof. Dr.H. Blenk, Privatdoz. Dr.-Ing.K. Gersten. — Ausführliche Fassung: Zur Berechnung der kompressiblen laminaren Grenzschicht mit kontinuierlich verteilter Absaugung, Bericht 61/28 des Inst. f. Strömungsmechanik der T. H. Braunschweig (1961); auszugsweise vorgetragen auf der Jahrestagung der Wiss. Ges. für Luftfahrt in Braunschweig, 9. 10.–12. 10. 1962. 相似文献
12.
Mechanics of granular materials: The discrete and the continuum descriptions juxtaposed 总被引:1,自引:0,他引:1
F. Froiio G. Tomassetti I. Vardoulakis 《International Journal of Solids and Structures》2006,43(25-26):7684-7720
In recent years a discussion could be followed where the pros and cons of the applicability of the Cosserat continuum model to granular materials were debated [Bardet, J.P., Vardoulakis, I., 2001. The asymmetry of stress in granular media. Int. J. Solids Struct. 38, 353–367; Kruyt, N.P., 2003. Static and kinematics of discrete Cosserat-type granular materials. Int. J. Solids Struct. 40, 511–534; Bagi, K., 2003. Discussion on “The asymmetry of stress in granular media”. Int. J. Solids Struct. 40, 1329–1331; Bardet, J.P., Vardoulakis, I. 2003a. Reply to discussion by Dr. Katalin Bagi. Int. J. Solids Struct. 40, 1035; Kuhn, M., 2003. Discussion on “The asymmetry of stress in granular media”. Int. J. Solids Struct. 40, 1805–1807; Bardet, J.P., Vardoulakis, I., 2003b. Reply to Dr. Kuhn’s discussion. Int. J. Solids Struct. 40, 1809; Ehlers, W., Ramm, E., Diebels, S., D’Addetta, G.A., 2003. From particle ensembles to Cosserat continua: homogenization of contact forces towards stresses and couple stresses. Int. J. Solids Struct. 40, 6681–6702; Chang, C.S., Kuhn, M.R., 2005. On virtual work and stress in granular media. Int. J. Solids Struct. 42, 3773–3793]. The authors follow closely this debate and try, with this paper, to provide a platform where the various viewpoints could find their position. We consider an ensemble of rigid, arbitrarily shaped grains as a set with structure. We establish a basic mathematical framework which allows to express the balance laws and the action–reaction laws for the discrete system in a “global” form, through the concepts of “part”, “granular surface”, “separately additive function” and “flux”. The independent variable in the balance laws is then the arbitrary part of the assembly rather than the single grain. A parallel framework is constructed for Cosserat continua, by applying the axiomatics established by [Noll, W., 1959. The foundation of classical mechanics in the light of recent advances in continuum mechanics. In: The axiomatic method, with special reference to Geometry and Physics, North-Holland Publishing Co., Amsterdam pp. 266–281, Gurtin, M.E., Williams, W.O., 1967. An axiomatic foundation of continuum thermodynamics. Arch. Rat. Mech. Anal. 26, 83–117, Gurtin, M.E., Martins, L.C., 1976. Cauchy’s theorem in classical physics. Arch. Rat. Mech. Anal. 60, 305–324]. The comparison between the two realisations suggests the microscopic interpretation for some features of Cosserat Mechanics, among which the asymmetry of the Cauchy-stress tensor and the couple-stress. 相似文献
13.
《Experimental Techniques》1987,11(10):16-17
Book reviewed in this article:
VIBRATION DAMPING By A.D. Nashif, D.I.G. Jones, J.P. Henderson
ELASTICITY, THEORY AND APPLICATIONS By H. Reismann and P.S. Pawlik
MODAL TESTING: THEORY AND PRACTICE By D.J. Evvins 相似文献
VIBRATION DAMPING By A.D. Nashif, D.I.G. Jones, J.P. Henderson
ELASTICITY, THEORY AND APPLICATIONS By H. Reismann and P.S. Pawlik
MODAL TESTING: THEORY AND PRACTICE By D.J. Evvins 相似文献
14.
Dr. F. Krause 《Archive of Applied Mechanics (Ingenieur Archiv)》1963,32(1):1-25
Ohne ZusammenfassungDissertation Göttingen. Referent Prof. Dr. A. Betz. Korreferent Prof. Dr. W. Tollmien. Die Arbeit wurde in der Aerodynamischen Versuchsanstalt Göttingen e. V. durchgeführt.Hiermit danke ich meinem verehrten Lehrer Herrn Prof. Dr. Albert Betz für die stete Förderung und seinen hilfreichen Rat bei der Durchführung der Arbeit. Herrn Dr. F. W. Riegels danke ich für wichtige Literaturhinweise und Herrn Dr. F. Keune für eine kritische Diskussion des Rechenverfahrens. 相似文献
15.
H. Peters 《Archive of Applied Mechanics (Ingenieur Archiv)》1931,2(1):92-107
Ohne ZusammenfassungMünchener Dissertation. Berichterstatter: Prof. Dr.-Ing. D. Thoma, Mitberichterstatter: Prof. Dr.-Ing. W. Nusselt. Die Arbeit wurde mit Unterstützung der Notgemeinschaft der deutschen Wissenschaft durchgeführt. 相似文献
16.
K. Klotter 《Archive of Applied Mechanics (Ingenieur Archiv)》1932,3(2):152-182
Ohne ZusammenfassungHabilitationsschrift Karlsruhe. Ref.: Prof. Dr.Th. Pöschl, Korref.: Prof.K. v. Sanden. 相似文献
17.
Part III of this work is concerned with the interaction of two penny-shaped cracks in the mid-plane of an elastic layer. Two cases, namely the stress free boundary case and the fixed boundary case, are considered. It is shown that these two cases are mathematically equivalent. As in Part I (G.A.C. Graham and Q. Lan, J. Theor. Appl. Fract. Mech. 20, 207–225 (1994) [1])_for the problems of an infinite solid and Part II (G.A.C. Graham and Q. Lan, J. Theor. Appl. Fract. Mech. 20, 227–237 (1994) [2]) of a semi-infinite solid, the problem is reduced to a system of Fredholm integral equations of the second kind. These integral equations are then solved when the crack size is small compared to the distance between them and the cracks are far away from the boundaries. It is also shown that the problem decouples when the cracks are subjected to normal loading and shear loading. Asymptotic solutions are presented for these two loadings. 相似文献
18.
The method (W.D. Collins, Proc. R. Soc. London A274, 507–528 (1963); W.S. Fu and L.M. Keer, Int. J. Eng. Sci. 7, 361–372 (1969) [1,2]) used to solve co-planar penny-shaped cracks is generalized to investigate interaction of arbitrarily located penny-shaped cracks. The solution (M.K. Kassir and G.C. Sih, Three-dimensional Crack Problems (Noordhoff International, 1975) [3]) for the problem of an isolated crack in an infinite solid is applied together with the superposition principle to reduce the problem to a system of Fredholm integral equations of the second kind. These integral equations are then solved iteratively when the cracks are far apart. Some asymptotic solutions for the stress intensity factors are presented and comparisons are made whenever possible. Numerical solutions reveal some interesting phenomena. 相似文献
19.
R. M. Zaidel 《Journal of Applied Mechanics and Technical Physics》1968,9(3):278-284
The discussion concerns the effects of ionizing radiation on pulse formation between conductors in a cable.I am indebted to G. M. Gandel'man, F. M. Gudin, G. F. Ioilev, and S. A. Kuchai for valuable discussions. 相似文献
20.
A study is made of the influence of a transverse pressure gradient on the mixing of reacting jets of fluorine and hydrogen. The real picture is simulated by a system of simplified Navier-Stokes equations. A comparison is made with calculations based on the complete Navier-Stokes equations and also boundary layer equations. Features of the shock waves are analyzed under conditions of strong heat release in the mixing layer. The influence of these features on the gain in laser situations is considered.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 18–23, May–June, 1982.We thank G. N. Volchkova, Yu. P. Golovachev, V. A. Pospelov, M. Kh. Strel'ts, and M. L. Shur for helpful discussions. 相似文献