scholarly journals Calculation and Prediction of Crushing Process of Al–Mg–Si Alloy Thin-Walled Components

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Hui Guo ◽  
Yunlai Deng ◽  
Shitong Fan ◽  
Renjie Pan
Keyword(s):  
Performance Indicator ◽  
Plastic Hinge ◽  
Peak Load ◽  
Bending Moment ◽  
Physical Relationship ◽  
Variation Characteristics ◽  
Three Stages ◽  
Thin Walled ◽  
Mathematical Relationships ◽  
Elastic Stage

Crushing performance is being widely investigated because it is the key performance indicator of the thin-walled beam structure in automobile safety components. In this study, five kinds of ageing state with different yield strengths were prefabricated with a self-developed KHC63 alloy. Using a rectangular tube profile, the physical relationship between crushing properties and mechanical properties, and the structure of the profile, were studied. According to variation characteristics, the crushing curve was divided into four typical stages: elastic stage, bending stage, compaction stage and folding stage. In the elastic stage, the peak load of the component is related to material elasticity and structure elasticity, and the relationship is approximately linear. In the bending stage, the driving factor of plastic hinge deformation is the bending moment, and it is always constant. In the compaction stage, the crushing curve correlates well with the cosine function. In the folding stage, the crushing process begins to lose stability and is hard to predict. The mathematical relationships between force and displacement were established according to the characteristics of each stage, and the calculated results were close to the measured results except for the folding stage. The deviation of the calculated energy absorption from the measured data in the first three stages is only 4.3%, but it is 10.6% in the folding stage. The calculation method used for the first three stages is, therefore, suitable.

Computer analysis of thin-walled concrete box beams

1989 ◽  
Vol 16 (6) ◽  
pp. 902-909 ◽  
Author(s):  
Shahbaz Mavaddat ◽  
M. Saeed Mirza
Keyword(s):  
Key Words ◽  
Computer Analysis ◽  
Shear Stresses ◽  
Shear Lag ◽  
Applied Loading ◽  
Box Beam ◽  
Box Beams ◽  
Three Stages ◽  
Thin Walled ◽  
Normal And Shear Stresses

Three computer programs, written in FORTRAN WATFIV, are developed to analyze straight, monolithically cast, symmetric concrete box beams with one, two, or three cells and side cantilevers over a simple span or over two spans with symmetric mid-span loadings. The analysis, based on Maisel's formulation, is performed in three stages. First, the structure is idealized as a beam and the normal and shear stresses are calculated using the simple bending theory and St-Venant's theory of torsion. The secondary stresses arising from torsional and distortional warping and shear lag are calculated in the second and third stages, respectively. The execution times on an AMDAHL 580 system are 0.02, 0.93, and 0.25 s for the three programs, respectively. The stresses arising in each stage of analysis are then superposed to determine the overall response of the box section to the applied loading. The results are compared with Maisel's hand calculations. Key words: bending, bimoment, box beam, computer analysis, FORTRAN, shear, shear lag, thin-walled section, torsion, torsional and distortional warping.

Geometrical Stiffness of Thin-Walled I-Beam Element Based on Rigid-Beam Assemblage Concept

2012 ◽  
Vol 28 (1) ◽  
pp. 97-106 ◽  
Author(s):  
J. D. Yau ◽  
S.-R. Kuo
Keyword(s):  
Stiffness Matrix ◽  
Virtual Work ◽  
Bending Moment ◽  
Beam Element ◽  
Narrow Beam ◽  
Cross Sectional ◽  
Geometric Stiffness ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Thin Walled

ABSTRACTUsing conventional virtual work method to derive geometric stiffness of a thin-walled beam element, researchers usually have to deal with nonlinear strains with high order terms and the induced moments caused by cross sectional stress results under rotations. To simplify the laborious procedure, this study decomposes an I-beam element into three narrow beam components in conjunction with geometrical hypothesis of rigid cross section. Then let us adopt Yanget al.'s simplified geometric stiffness matrix [kg]12×12of a rigid beam element as the basis of geometric stiffness of a narrow beam element. Finally, we can use rigid beam assemblage and stiffness transformation procedure to derivate the geometric stiffness matrix [kg]14×14of an I-beam element, in which two nodal warping deformations are included. From the derived [kg]14×14matrix, it can take into account the nature of various rotational moments, such as semi-tangential (ST) property for St. Venant torque and quasi-tangential (QT) property for both bending moment and warping torque. The applicability of the proposed [kg]14×14matrix to buckling problem and geometric nonlinear analysis of loaded I-shaped beam structures will be verified and compared with the results presented in existing literatures. Moreover, the post-buckling behavior of a centrally-load web-tapered I-beam with warping restraints will be investigated as well.

Numerical Investigation of Cross-Section on Aluminum A6063 Thin-Walled Structures under Low-Velocity Impact Loading

2014 ◽  
Vol 1019 ◽  
pp. 96-102
Author(s):  
Ali Taherkhani ◽  
Ali Alavi Nia
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Cross Sections ◽  
Peak Load ◽  
Circular Cross Section ◽  
Absorption Capacity ◽  
Energy Absorption Capacity ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
Crush Strength

In this study, the energy absorption capacity and crush strength of cylindrical thin-walled structures is investigated using nonlinear Finite Elements code LS-DYNA. For the thin-walled structure, Aluminum A6063 is used and its behaviour is modeled using power-law equation. In order to better investigate the performance of tubes, the simulation was also carried out on structures with other types of cross-sections such as triangle, square, rectangle, and hexagonal, and their results, namely, energy absorption, crush strength, peak load, and the displacement at the end of tubes was compared to each other. It was seen that the circular cross-section has the highest energy absorption capacity and crush strength, while they are the lowest for the triangular cross-section. It was concluded that increasing the number of sides increases the energy absorption capacity and the crush strength. On the other hand, by comparing the results between the square and rectangular cross-sections, it can be found out that eliminating the symmetry of the cross-section decreases the energy absorption capacity and the crush strength. The crush behaviour of the structure was also studied by changing the mass and the velocity of the striker, simultaneously while its total kinetic energy is kept constant. It was seen that the energy absorption of the structure is more sensitive to the striker velocity than its mass.

scholarly journals Flexural-Torsional Vibration of Thin-Walled Beams Subjected to Combined Initial Axial Load and End Bending Moment: Application to the Design of Saw Tooth Blades

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Van Binh Phung ◽  
Anh Tuan Nguyen ◽  
Hoang Minh Dang ◽  
Thanh-Phong Dao ◽  
V. N. Duc
Keyword(s):  
Boundary Conditions ◽  
Axial Load ◽  
Stability Boundary ◽  
Bending Moment ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Rayleigh Method ◽  
Thin Walled ◽  
The Stability ◽  
Fixed End

The present paper analyzes the vibration issue of thin-walled beams under combined initial axial load and end moment in two cases with different boundary conditions, specifically the simply supported-end and the laterally fixed-end boundary conditions. The analytical expressions for the first natural frequencies of thin-walled beams were derived by two methods that are a method based on the existence of the roots theorem of differential equation systems and the Rayleigh method. In particular, the stability boundary of a beam can be determined directly from its first natural frequency expression. The analytical results are in good agreement with those from the finite element analysis software ANSYS Mechanical APDL. The research results obtained here are useful for those creating tooth blade designs of innovative frame saw machines.

Effects of Wall Thickness and Crush Initiators Position under Experimental Drop Test on Square Tubes

2017 ◽  
Vol 865 ◽  
pp. 612-618 ◽  
Author(s):  
M. Malawat ◽  
Jos Istiyanto ◽  
D.A. Sumarsono
Keyword(s):  
Energy Absorption ◽  
Tube Wall ◽  
Impact Load ◽  
Peak Load ◽  
Load Force ◽  
Drop Height ◽  
Thin Walled ◽  
The Impact ◽  
Initial Peak ◽  
Load Mass

Crush initiators are the weakest points to reduce initial peak load force with significant energy absorption ability. The objective of this paper is to study the effects of square tube thickness and crush initiators position for impact energy absorber (IEA) performance on thin-walled square tubes. Two square tubes having thickness about 0.6 mm (specimen code A) and 1 mm (specimen Code C) were tested under dynamic load. The crushing initiator is designed around the shape of the tube wall and has eight holes with a fixed diameter of 6.5 mm. In the experiment, the crushing initiator was determined at 5 different locations on the specimen wall. These locations are 10 mm, 20 mm. 30 mm, 40 mm, and 50 mm measured from the initial collision position of the specimen tested. The impact load mass was about 80 kg and had a drop height of about 1.5 m. Using the simulation program of the LabVIEW Professional Development System 2011 and National Instrument (NI) 9234 software equipped with data acquisition hardware NI cDAQ-9174 the signal from the load cell was sent to a computer. By controlling the thickness of the thin-walled square tube, the peak loading force can be decreased by approximately 56.75% and energy absorption ability of IEA can be increased approximately to 11.83%. By using different thin-walled square tube can produce different best crush initiators position with the lowest peak load force.

The Lateral Buckling of Steel-Concrete Composite П-Beam

2008 ◽  
Vol 400-402 ◽  
pp. 287-293
Author(s):  
Li Zhong Jiang ◽  
Lin Lin Sun ◽  
Xing Li
Keyword(s):  
Bending Moment ◽  
Computing Methods ◽  
Lateral Buckling ◽  
Computing Model ◽  
Negative Moment ◽  
Numerical Computing ◽  
Negative Bending ◽  
The Stability ◽  
Simplified Calculation ◽  
Elastic Stage

Based on the theoretical analysis of steel-concrete composite П-beam’s lateral buckling, the computing model and simplified computing model on the stability of composite П-beams are brought forward. According to above two models, composite beam’s lateral buckling is studied in negative moment regions using the energy method, and the formulas which are used to calculate critical bending moment in negative moment regions in the elastic stage are deduced. Compared with other stability theories and methods, this paper represents the design correction and suggestion about the stability of composite П-beam in negative bending regions. Moreover, the simplified calculation method, which is used to compute the lateral critical buckling moment of steel-concrete composite П-beam loaded by equal-end moment, not only simplifies the computing process, the computing results also have the equivalent accuracy with numerical computing methods.

Ron Resch Origami Pattern Inspired Energy Absorption Structures

2018 ◽  
Vol 86 (1) ◽  
Author(s):  
Zhe Chen ◽  
Tonghao Wu ◽  
Guodong Nian ◽  
Yejie Shan ◽  
Xueya Liang ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Energy Absorption ◽  
Impact Energy ◽  
Plastic Hinge ◽  
Honeycomb Structure ◽  
Experimental Characterization ◽  
Collapse Mode ◽  
Thin Walled ◽  
Force Reduction ◽  
Absorb Impact Energy

Energy absorption structures are widely used in many scenarios. Thin-walled members have been heavily employed to absorb impact energy. This paper presents a novel, Ron Resch origami pattern inspired energy absorption structure. Experimental characterization and numerical simulations were conducted to study the energy absorption of this structure. The results show a new collapse mode in terms of energy absorption featuring multiple plastic hinge lines, which lead to the peak force reduction and larger effective stroke, as compared with the classical honeycomb structure. Overall, the Ron Resch origami-inspired structure and the classical honeycomb structure are quite complementary as energy absorption structures.

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