Mode transitions in the impact crushing of thin-walled tubes

Transitions impact walled

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This paper presents a new technique for mode transitions in the impact crushing of thin-walled tubes energy absorption system which is simpler than other designs in production. mode transitions in the impact crushing of thin-walled tubes Thin-walled tubes have always considered as energy absorption systems by researchers. Dents are sometimes added to the surface mode transitions in the impact crushing of thin-walled tubes in order to reduce the initial buckling force. This study focuses on a thin-walled square tube with diaphragms (TSTD) as an energy-absorbing structure. Thin-walled tubes subjected to axial crushing have been extensively employed as energy absorption devices in transport vehicles.

One of the mode transitions in the impact crushing of thin-walled tubes earliest investigations on the crushing behavior of thin-walled sections lled with lightweight polyurethane foam (PU foam) was conducted by Lampinen and Jeryan 7. ; Zhang and Zhang,, ). In general, the magnesium tubes absorbed energy mainly by fracture. (1987) conducted experiments using low-fins tube and obtained different values of mode transitions in the impact crushing of thin-walled tubes A and B. circular thin-walled mild-steel columns subjected to quasi-static and dynamic axial loading. transition from a progressive mode to mode transitions in the impact crushing of thin-walled tubes a mixed mode transitions in the impact crushing of thin-walled tubes mode appeared over a large range of lengths, concluding the fact that the length of the tube does affect its collapse mode 12. Topic-J: Impact and Crashworthiness -736- METHODOLOGY In this mode transitions in the impact crushing of thin-walled tubes paper, we intend to investigate the transition of the folding mode of the thin-walled tubes after foam-filling through an analytical model based on the kinematically admissible mechanisms.

impact energy absorption analysis of different thin -walled tubes with and without reinforcement. a thesis submitted to the university of manchester for the. In this study, quasi-static (≅0. Introduction As in the case of the experimental studies on the axial impact of thin-walled square tubes in the previous study 1,2, the crushing modes during low and high velocity impacts are transitions different. Multi-cell tubes have got special attention in recent years because of superior energy absorption. Effect of foam-filling on collapse mode transition of thin-walled circular columns under axial compression: analytical, numerical and experimental studies.

The objective is to. Quasi-static and dynamic axial crushing tests have been performed on circular thin-walled sections made of three materials: 304 stainless steel, aluminium alloy 6063- T6, and mild steel. For conventional tubes subject to axial crushing, they usually mode transitions in the impact crushing of thin-walled tubes exhibit a high initial peak force and large fluctuation. Square Tubes The torsional crushing problem of thin-walled square tubes will be solved numerically in this chapter by using the non-linear explicit finite element code PAM-CRASH.

67mm/s) and impact mode transitions in the impact crushing of thin-walled tubes (3~4m/s) crushing tests of some thin-walled regular polygonal tubes were performed by the testing devices of Amsler, Instron and the dropping-weight types respectively for the crush angle φ = 0, 10, 20, and 30° to investigate the effects of strain rate, crush angle and. By introducing patterns to the thin-walled tube, the crushing mode can be altered so that better energy absorbing performance may be achieved. Quasi-static and dynamic axial crushing tests were performed on thin-walled square tubes and spot mode transitions in the impact crushing of thin-walled tubes welded top-hat sections made of high-strength steel grade DP800.

The tests were arranged to investigate the mode transitions during the impact crushing of thin-walled tubes and the three mode transitions in the impact crushing of thin-walled tubes materials were chosen for their distinctive individual characteristics,. The axial impact of thin. In case of a perfect tube, oscillation of crushing force and erratic buckling mode is natural. The explicit finite element code ABAQUS was then em-ployed to perform the numerical studies inview of mitigating the. Thin-walled tubular structures are widely used as energy absorbing devices. The derivations of the model start from the basic principle mode transitions in the impact crushing of thin-walled tubes of energy. 8 showed that transitions in the collapse mode of circular aluminium tubes mode transitions in the impact crushing of thin-walled tubes may be. Crash tube abstract The axial crushing and crashing of thin-walled high-strength steel tubes is performed using 3D-shell finite elements and an mode transitions in the impact crushing of thin-walled tubes implicit time integration scheme.

Thin-walled tube mode transitions in the impact crushing of thin-walled tubes is one of the most commonly used energy absorber. The twisting deformation pattern of the tube and the sectional buckling mode are then. () also focused on tube surface effect by considering low fin, Turbo-BII, Thermo-EXCEL-E, and Turbo-CSL tubes, and. Quasi-static and impact tests are performed and the load-displacement curves are studied. Thin-walled structures, v. Energy absorption capability of thin-walled aluminium tubes under crash loading 1737 Experimental test 29 Numerical test by Karagiozova et al. Recently, Gupta et al. 788-797: Summary: This paper presents a study of the effectiveness of adding a buckling initiator which is used to reduce the initial peak force of a thin-walled circular tube under axial impact loadings.

Sonmezn Department of Mechanical Engineering, Bogazici University, Istanbul, Bebek 34342, Turkey article info Article history: Received 2 October Received in revised form 7 July Accepted 7 July Keywords: Thin-walled mode transitions in the impact crushing of thin-walled tubes tubes. In the oblique impact, the crushing mode transfers from axial crushing dominated mode to bending dominated mode with the increase of the impact angle. Abstract In this study, a series of axial crush tests were performed on AZ31B magnesium and A6063 aluminum thin-walled circular tubes to investigate mode transitions in the impact crushing of thin-walled tubes the influence law of the failure mode and energy absorption capacity dictated by length/diameter (L/D) ratio, compression speed, and induced features as well as their difference.

To mode transitions in the impact crushing of thin-walled tubes investigate the layout strategy of mode transitions in the impact crushing of thin-walled tubes diaphra. In the oblique impact, the crushing mode transfers from axial crushing dominated mode to bending dominated mode with the increase of the impact angle. mechanisms and the corresponding collapse mode along with its energy absorption of the thin-walled tubes were investigated in detail for various aspect ratios (0. Key words: thin-walled square tube, quasi-static, dynamic progressive buckling, general mixed collapse mode. The average crushing load for each mode is predicted from the super-folding element theory, mode transitions in the impact crushing of thin-walled tubes which was proposed from the previous investigation on the axial crushing of square columns. 2 reported on the axial crushing behaviour of thin-walled mild steel square and circular tubes struck by relatively heavy masses traveling up to 12 rrds. Hopperstad, 1996, Static and dynamic axial crushing of square thin-walled aluminium extrusions, International Journal of Impact Engineering, Volume 18, Issues 7–8, October– December 1996, Pages 949–968. Experiments prove that in order to achieve the real collapsing shape of tubes under axial loads in numerical simulations, an initial geometric imperfection corresponding to the plastic buckling modes should.

In normal impact, the hierarchical steel tubes have progressive folding and global folding, depending on the cell number and the thickness of the sandwich wall. A comparison is made with. transitions Singace and E1-Sobky studied the effect of corrugations on the crushing behavior of circular tubes. The effect of mode transitions in the impact crushing of thin-walled tubes the implementation of circular holes as crush initiators to the crushing characteristics mode transitions in the impact crushing of thin-walled tubes of mild steel square tubes: experimental and numerical simulation. In Part I, the experimental studies are presented. Crush mechanics of thin-walled tubes Chen, Dai-heng.

The tests were arranged to investigate the mode transitions during the impact crushing of thin-walled tubes and the three materials were chosen for their distinctive individual characteristics, such as strain rate sensitive properties, pronounced strain hardening, etc. Tarigopula et al 2, investigated the axial crushing behavior of thin walled high strength steel sections. The tests were arranged to investigate the mode transitions during the impact crushing of thin-walled strain rate sensitive properties, pronounced strain. In the axial crushing test of the regular polygonal tube, if the number of angles was small enough, it showed a certain inherent wrinkle mode, and the mean buckling load. The current paper presents further investigations into the crushing behaviour of circular aluminium tubes subjected to axial impact load. International Journal of Crashworthiness: Vol. mode transitions in the impact crushing of thin-walled tubes Besides, the stress wave propagation phenomena during an axial impact was also focused in the work published mode transitions in the impact crushing of thin-walled tubes by Karagiozova and Jones 5–7.

Circumferential grooves are introduced in the tube to force the plastic deformation which helps to control the buckling mode. A mode transitions in the impact crushing of thin-walled tubes rigid-plastic material model and a kinematically admissible model are involved in this theory. 03mm/s), low-speed (6. This novel model is a thin-walled tube with perforation.

They concluded that the foam lling stabilizes the deformation of thin-walled tubes. From the viewpoint of improving both the crash safety and the fuel efficiency, various shaped thin-walled tubes have been utilized as energy absorbers of automobiles such as front side members, crash boxes and so forth. Conventionally, they have a square or rectangular section, either straight or tapered. Long cylindrical tubes exhibit poor energy absorption due to Euler’s buckling mode when they are mode transitions in the impact crushing of thin-walled tubes used to absorb impact energy. In this paper, a novel approach is proposed to investigate the progressive collapse damage of prismatic thin walled metal columns with different regular cross sections, under the action of axial quasi-static and impact loads. Optimal shape design of thin-walled tubes under high-velocity axial impact loads Niyazi Tanlak, Fazil O. Main Crush mode transitions in the impact crushing of thin-walled tubes mechanics of thin-walled tubes. In spite of the complex behaviour of the specimens, some empirical relations were obtained for the mode transitions between dynamic progressive buckling and.

It can dissipate impact energy through different deformation modes via axial or lateral conditions. 29 FE model current study N-1-B N-2-C N-3-D N-4-E Figure 2. 47, (6-7),, JUN-JUL, p. Thin-walled tubes can dissipate the impact energy under differ-ent mechanism such as fracture, splitting, bending, tension, shear and plastic deformation. The effects of geometry on falling-film transitions for round tubes have also been studied.

The finite element modelling and simulation techniques are reviewed first. mode transitions in the impact crushing of thin-walled tubes Deformation mode of square tubes from experimental and FE model of 29 and in comparison to FE model of current study. Then mode transitions in the impact crushing of thin-walled tubes Tasdemirci 13 carried out an investigation of the effect of tube end mode transitions in the impact crushing of thin-walled tubes constraining on the axial crushing behavior aluminum tubes. thin-walled tubes seems to improve crush stability and energy absorption capacity 4-6. The calculated results are compared with published experimental data and results obtained using explicit time integration. This two-part paper presents the results of experimental and numerical work mode transitions in the impact crushing of thin-walled tubes on the crushing characteristics of square tubes, with blast-induced imperfections, subjected to axial load.

Mode transitions in the impact crushing of thin-walled tubes

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