scholarly journals Simulation and Experiment of a Kind of Thin-Walled Tube Crushing Member Used for Antiimpact Column

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Cheng‐long Wang ◽  
Yifang Chen ◽  
QingLiang Zeng ◽  
Guoming Liu
Keyword(s):  
Wall Thickness ◽  
Reaction Force ◽  
Hollow Structure ◽  
Peak Force ◽  
Elastic Displacement ◽  
Ring Mode ◽  
Thin Walled Tube ◽  
Simulation And Experiment ◽  
Thin Walled ◽  
Initial Peak

In order to solve the problem of poor antiimpact ability of hydraulic support under rock bursting, a kind of thin-walled cylinder crushing component used in the composite spiral antiimpact device was developed, and different structural models were proposed and simulated. On this basis, the model was verified by experiments. The results show that the arrangement of the hollow structure can restrain the ring mode deformation and Euler instability of the tube member in the crushing yield and can carry out the buckling deformation according to the expected crushing force during the compression deformation process and effectively reduce the initial peak force. The arrangement of guide grooves can make the buckling deformation more stable and regular, which can effectively reduce the initial peak force and elastic displacement. With the smaller wall thickness and the smaller wall thickness of the induced groove, the effective deformation yield stroke of the crushing member increases, and the initial peak force, total energy absorption, average reaction force, and elastic displacement decrease. The simulation results are consistent with the experimental results which will be used in the future works.

A Novel Origami Crash Box With Varying Profiles

2013 ◽  
Author(s):  
Jiayao Ma ◽  
Zhong You
Keyword(s):  
Numerical Simulation ◽  
Energy Absorption ◽  
Cross Sections ◽  
Peak Force ◽  
Geometric Imperfection ◽  
Axial Crushing ◽  
Collapse Mode ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Initial Peak

Crash boxes in automobiles are often made from thin-walled tubes. They are designed to absorb energy when subjected to axial crushing. In this paper we present a novel crash box known as the origami crash box. It is produced by pre-folding the surface of a thin-walled tube according to a developable origami pattern. The pre-folded surface serves both as a type of geometric imperfection to lower the initial peak force, and as a mode inducer to trigger a collapse mode that is more efficient in terms of energy absorption. Numerical simulation of quasi-static axial crushing of the origami crash box has shown that a new collapse mode deemed the completed diamond mode can be triggered in tubes with square, rectangular, and polygonal cross sections and tapered shapes, leading to both a substantial gain in overall energy absorption, while at the same time, a reduction in initial peak force.

scholarly journals Evidence for Stacking Faults in Multiaxial Strained Alpha-Brass

1983 ◽  
Vol 27 ◽  
pp. 363-368
Author(s):  
R. B. Roof
Keyword(s):  
Wall Thickness ◽  
External Surface ◽  
Large Strain ◽  
Stacking Faults ◽  
Multiaxial Loading ◽  
Tube Surface ◽  
Line Broadening ◽  
X Ray ◽  
Thin Walled Tube ◽  
Thin Walled

As part of a program studying the effects of large strain deformations resulting from multiaxial loading to a variety of materials, a thin walled tube (0.46” O.D. x 0.02” wall thickness) of 70-30 Brass was subjected to strain deformation in the following directions 1) along the tube axis, εz = 0.3393; 2) circumferential around the tube surface, εθ = -0.0121; 3) perpendicular to the wall thickness, εR = 0.3514. This report describes the results of an x-ray examination of the external surface of the tube by the line broadening technique.

Axial Crushing of Thin-Walled Tubes With Kite-Shape Pattern

2015 ◽  
Author(s):  
Degao Hou ◽  
Yan Chen ◽  
Jiayao Ma ◽  
Zhong You
Keyword(s):  
Energy Absorption ◽  
Peak Force ◽  
Great Promise ◽  
Axial Crushing ◽  
Crushing Force ◽  
Collapse Mode ◽  
Shape Pattern ◽  
The Mean ◽  
Thin Walled ◽  
Initial Peak

Thin-walled tubes are widely used as energy absorption devices in automobiles, designed to protect the costly structures and people inside during an impact event through plastic deformation. They show excellent performance under axial loading in terms of weight efficiency, stroke distance and total energy absorption, but also have the disadvantage that the crushing force is not uniform during deformation process, especially with the existence of a high initial peak force. Recently, pattern design on tubular structures has received increasing attention. It has been found that, if the surface of a tube is pre-folded according to an origami pattern, the collapse mode of the tube can be altered, leading to changes in energy absorption performance. In this paper, we present a series of origami patterned tubes with a kite-shape pattern that is constructed by joining two pieces of Miura-ori. First of all, the geometry of the pattern is presented. We develop a theoretical model to predict the energy absorption associated with the axial crushing of the patterned tubes and derive a mathematical formula to calculate the mean crushing force accordingly. Secondly, a family of origami tubes with various profiles are designed, and their performances subjected to quasi-static axial crushing are numerically investigated. A parametric study is also conducted to establish the relationship between the pre-folded angle of the pattern and the initial peak force as well as the mean crushing force. Numerical results show that introducing patterns to thin-walled tubes offers three advantages in comparison with conventional tubes, i.e., a lower initial peak force, a more uniform crushing load, and a stable and repeatable collapse mode. A 36.0% increase in specific energy absorption and 67.2% reduction in initial peak force is achieved in the optimum case. The new origami patterned tubes show great promise as energy absorption devices.

An Approach for Analysis of Bulged Profile and Thickness Distribution of Tube in Free Hydro-Bulging Process

2012 ◽  
Vol 499 ◽  
pp. 127-131
Author(s):  
Xiao Feng Liu ◽  
Lian Fa Yang ◽  
Yu Xian Zhang
Keyword(s):  
Mathematical Model ◽  
Plastic Deformation ◽  
Finite Element ◽  
Wall Thickness ◽  
Deformation Behavior ◽  
Thickness Distribution ◽  
Plastic Deformation Behavior ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Tubular Components

Tubular components are widely used in the areas of automotive and aerospace industries due to their excellent properties. A mathematical model considering the bulged region as a parabola curve is proposed to examine the plastic deformation behavior of a thin-walled tube during the free hydro-bulged process. The finite element simulations of the free hydro-bulging process are carried out to verify the approach indirectly. The results indicate that the model is accurate and acceptable to figure out the circumferential radius, wall thickness and axial radius of the bulged profile.

Process Parameter Analysis of Higher D/T Ratio Tube Formed From Sheet Hydroforming

2017 ◽  
Author(s):  
Duanyang Tian ◽  
Xuedao Shu ◽  
Yilun Wei ◽  
Yu Wang
Keyword(s):  
Wall Thickness ◽  
Large Diameter ◽  
Hydraulic Pressure ◽  
Blank Holder Force ◽  
Blank Holder ◽  
Forming Quality ◽  
Sheet Hydroforming ◽  
Thickness Uniformity ◽  
Thin Walled Tube ◽  
Thin Walled

As a core part of the aero engine casing, the thin-walled tube with large diameter usually formed by sheet hydroforming presents high forming precision and forming quality. In this paper, the appropriate hydraulic pressure and blank holder force should be identified to control the wall thickness uniformity of N08811 alloy tube with large diameter. Firstly, the stress-strain curve of this material at room temperature is obtained from deep drawing tests. Subsequently, within the allowable range of springback and wrinkling errors, finite element simulation and the uniform test design are performed to investigate the effect of the multi-level process parameters on the thickness uniformity of the higher D/t ratio tube. Results show that the blank holder force and the hydraulic pressure produce significant effects on the wall thickness uniformity. Finally, the regression analysis is further carried out for the computational results from uniform experimental design experiments. The optimized process parameters are then obtained and the wall thickness uniformity of the tube is improved. These results provide a theoretical reference for improving the forming quality of thin-walled tube with large diameter.

Theoretical, Numerical and Experimental Investigation of the Effects of Manufacturing Process Parameters on Thin-Walled Tube Bending Defects

2009 ◽  
Vol 83-86 ◽  
pp. 1107-1112
Author(s):  
J. Taheri Kahnamouei ◽  
Mohammad Sedighi
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Thickness Ratio ◽  
Outer Diameter ◽  
Tube Bending ◽  
Effective Parameters ◽  
Bending Process ◽  
Thin Walled Tube ◽  
Bending Radius ◽  
Thin Walled

The aim of this paper is to survey thin-walled tube bending process (without use of mandrel and booster). In tube bending process there are several effective parameters such as wall thickness, outer diameter-to-wall thickness ratio, and centerline bending radius-to-outer diameter ratio. Any mismatch in selecting these parameters would cause defects like wrinkling, variation in wall thickness, and cross section distortion. Firstly, the effects of these parameters on the initiation of the wrinkle, depth of wrinkling, change in wall thickness, and cross section distortion are studied. For this purpose, an FE commercial code has been used to simulate the process. Then, a series of experimental tests have been carried out to verify the results simulation. A comparison between analytical and experimental results shows a reasonable agreement with each other. Based on this comparison, it has been observed that there is a critical bending radius for any tube with a certain radius and thickness, in which the wrinkling begins to occur. For a certain bending angle and radius, it have been observed that the depth of wrinkling, change in wall thickness, and cross section distortion increase with reduction in wall thickness and outer diameter-to-wall thickness ratio

Tube of Least Weight for Given Torsional Stiffness

1953 ◽  
Vol 57 (505) ◽  
pp. 45-46
Author(s):  
H. B. Howard
Keyword(s):  
Wall Thickness ◽  
Torsional Stiffness ◽  
Applied Torque ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Fixed End

Consider a thin-walled tube fixed at one end and subject to torque of known distribution. The problem is to find how the thickness of the wall should vary along the length so that the weight is a minimum for a given angle of twist at the free end.At distance x from the fixed end, let T be the applied torque, A the enclosed area of the tube, P its perimeter and y the wall thickness.

scholarly journals SIZE EFFECT OF WELDED THIN-WALLED TUBULAR JOINTS

2007 ◽  
Vol 07 (01) ◽  
pp. 101-127 ◽  
Author(s):  
FIDELIS RUTENDO MASHIRI ◽  
XIAO-LING ZHAO ◽  
MANFRED A. HIRT ◽  
ALAIN NUSSBAUMER
Keyword(s):  
Size Effect ◽  
Wall Thickness ◽  
Hot Spot ◽  
Fatigue Behavior ◽  
T Joints ◽  
Hot Spot Stress ◽  
Tubular Joints ◽  
Thin Walled Tube ◽  
Simple Extrapolation ◽  
Thin Walled

This paper clarifies the terminologies used to describe the size effect on fatigue behavior of welded joints. It summarizes the existing research on size effect in the perspective of newly defined terminologies. It identifies knowledge gaps in designing tubular joints using the hot spot stress method, i.e. thin-walled tubular joints with wall thickness less than 4 mm and thick-walled tubular joints with wall thickness larger than 50 mm, or diameter to thickness ratio less than 24. It is the thin-walled tubular joints that are addressed in this paper. It is found that thin-walled tube-plate T-joints do not follow the conventional trend: the thinner the section is, the higher the fatigue life. It is also found that simple extrapolation of existing fatigue design curves may result in unsafe design of thin-walled tube–tube T-joints. The effect of chord stiffness on fatigue behavior of thin-walled tubular T-joints is also discussed.

Microstructure and Texture Evolution of 0.6 mm Ultra-Thin-Walled Tubes of Magnesium Alloys Fabricated by Multi-Pass Variable Wall Thickness Extrusion (VWTE)

2020 ◽  
Vol 993 ◽  
pp. 427-433
Author(s):  
Zhao Ming Yan ◽  
Zhen Dong Lian ◽  
Min Fang ◽  
Zhi Min Zhang ◽  
Jia Xuan Zhu ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Texture Evolution ◽  
Extrusion Direction ◽  
Area Reduction ◽  
Average Grain Size ◽  
Coarse Grains ◽  
Thin Walled Tube ◽  
Variable Wall Thickness ◽  
Thin Walled ◽  
Variable Wall

AZ80+0.4%Ce alloy ultra-thin-walled tube with a wall thickness of 0.6 mm was fabricated by multi-pass variable wall thickness extrusion (VWTE) at 693 K. Microsturcture and texture evolution were investigated. The results indicate that the average grain size decreases from ~47 μm of extruded alloy to ~8.9 μm after 5 passes VWTE. The total area reduction of Mg alloy tube is 91 %. Homogeneity of microstructure is improved obviously and the morphology of Mg17Al12 phases in coarse grains and fine DRXed grains exhibit lamellar and granular shapes, respectively. In addition to the microstructure evolution, the VWTEed tubes showed a strong texture of (0001) planes, and the intensity decreased with deformation increasing to 4 passes. After 5p-VWTE, a strong texture characterized by (0001) pole tilting 20 degrees rotated from extrusion direction (ED) towards normal direction (ND).

Crush Characteristics and Energy Absorption of Thin-Walled Tubes with Through-Hole Crush Initiators

2014 ◽  
Vol 606 ◽  
pp. 181-185 ◽  
Author(s):  
S. Kanna Subramaniyan ◽  
Arun Kumar Kananasan ◽  
Mohd Radzi Mohamed Yunus ◽  
Shahruddin Mahzan ◽  
Mohd Imran Ghazali
Keyword(s):  
Experimental Investigation ◽  
Energy Absorption ◽  
Static Loading ◽  
Absorption Capacity ◽  
Peak Force ◽  
Energy Absorption Capacity ◽  
Steel Tubes ◽  
Thin Walled ◽  
Through Hole ◽  
Initial Peak

An experimental investigation was conducted to compare the crush characteristics and energy absorption capacity of circular and square tubes with located through-hole crush initiator. Circular through-holes were fabricated at three different configurations based on location into steel tubes which had a length of 200 mm. Furthermore, two different side configurations along the tube were considered for introducing the crush initiators. The results found that adding crush initiator onto the tubes were effectively reduced the initial peak force of a thin-walled circular and square tubes under axial quasi-static loading. The peak crush force was reduced within a range 3-10% and 5-16% for circular and square tubes respectively when compared with corresponding tubes without crush initiator. Moreover, the energy absorption capacity of the tubes was independent with the incorporation of through-hole crush initiators. However, the energy absorption of circular and square tubes were slightly decreases when compared with the tubes fabricated four sided crush initiation and tubes without crush initiator. Overall, the effect of location and number of crush initiation proved significantly influences the initial peak forces while maintain the energy absorbed.

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