scholarly journals Dynamic Simulation on Impact Test of Vehicle Wheel

2011 ◽  
Vol 2-3 ◽  
pp. 890-893
Author(s):  
Yu Qing Zheng ◽  
Bing Li ◽  
Zhen Lin Wang
Keyword(s):  
Impact Test ◽  
Equivalent Plastic Strain ◽  
Numerical Procedure ◽  
Strain Curve ◽  
Computation Time ◽  
Free Fall ◽  
Computational Time ◽  
Mass Scaling ◽  
Axial Tensile ◽  
The Impact

This paper establishes a numerical procedure to predict the aluminum wheel performance during the impact test. The dynamic finite element solver, Ansys-Lsdyna970, is used. In order to save the computation time, the striker is assigned with an initial velocity, which is equal to the velocity reached during the free-fall period upon release. Mass scaling method is also utilized to further reduce computational time. Equivalent plastic strain is used as the damage indicator to judge pass or fail for the dynamic impact test. The true stress-strain curve is obtained from a uni-axial tensile test of A356-T6 samples machined from a prototype wheel. Simulation results show that plastic deformation tends to be localized around spoke-to-hub junction area. Studies on a recent prototype wheel revealed good correlation between experimental results and numerical prediction.

scholarly journals Numerical Modelling of Ballistic Impact Response at Low Velocity in Aramid Fabrics

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2087 ◽  
Author(s):  
Norberto Feito ◽  
José Antonio Loya ◽  
Ana Muñoz-Sánchez ◽  
Raj Das
Keyword(s):  
Numerical Model ◽  
Mechanistic Model ◽  
Computation Time ◽  
Impact Angle ◽  
Impact Response ◽  
Low Velocity Impact ◽  
Computational Time ◽  
Low Velocity ◽  
Aramid Fabrics ◽  
The Impact

In this study, the effect of the impact angle of a projectile during low-velocity impact on Kevlar fabrics has been investigated using a simplified numerical model. The implementation of mesoscale models is complex and usually involves long computation time, in contrast to the practical industry needs to obtain accurate results rapidly. In addition, when the simulation includes more than one layer of composite ply, the computational time increases even in the case of hybrid models. With the goal of providing useful and rapid prediction tools to the industry, a simplified model has been developed in this work. The model offers an advantage in the reduced computational time compared to a full 3D model (around a 90% faster). The proposed model has been validated against equivalent experimental and numerical results reported in the literature with acceptable deviations and accuracies for design requirements. The proposed numerical model allows the study of the influence of the geometry on the impact response of the composite. Finally, after a parametric study related to the number of layers and angle of impact, using a response surface methodology, a mechanistic model and a surface diagram have been presented in order to help with the calculation of the ballistic limit.

Incline Impact: A Case Study

2021 ◽  
Vol 9 (1) ◽  
pp. 327-333
Author(s):  
S. Malasri ◽  
◽  
T. Podesta ◽  
R. Moats ◽  
T. Waddell ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Impact Test ◽  
Free Fall ◽  
Rolling Friction ◽  
Shock Test ◽  
Platform Location ◽  
Christian Brothers ◽  
Impact Tester ◽  
The Impact

An incline impact test can be used as a shock test in lieu of a drop test in several test protocols, including ISTA Procedure 1A [1]. Some test protocols, such as ISTA Procedure 1E [2], only allow for an incline impact test and horizontal impact test. In this case study, a graph was developed for a 500-lb impact tester at Christian Brothers University (CBU) Packaging Laboratory. It determines sliding platform location on the incline for a given packaged-product weight to meet the impact velocity recommended by the International Safe Transit Association (ISTA). One station of the platform location higher than the station obtained from the graph is recommended to ensure the meeting of ISTA recommended impact velocity. It is well known that weight is not used in impact velocity of a free fall drop. However, this case study shows that weight contributes to impact velocity of an incline impact test. It contributes to the rolling friction. A heavier weight yields a smaller coefficient of rolling friction ( 𝜇𝑘 ), which results in a higher impact velocity. The coefficient of rolling friction for CBU’s incline impact tester can be computed from 𝜇𝑘 = −9 −5𝑤 + 0.1092, where w is the total weight of the sliding platform and packaged product.

scholarly journals Static and Dynamic Performances of Chopped Carbon-Fiber-Reinforced Mortar and Concrete Incorporated with Disparate Lengths

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 972
Author(s):  
Yeou-Fong Li ◽  
Kun-Fang Lee ◽  
Gobinathan Kadagathur Ramanathan ◽  
Ta-Wui Cheng ◽  
Chih-Hong Huang ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Blast Wave ◽  
Carbon Fibers ◽  
Impact Test ◽  
Free Fall ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced ◽  
The Impact

The impact load, such as seismic and shock wave, sometimes causes severe damage to the reinforced concrete structures. This study utilized different lengths of chopped carbon fibers to develop a carbon-fiber-reinforced mortar (CFRM) and carbon-fiber-reinforced concrete (CFRC) with high impact and anti-shockwave resistance. The different lengths (6, 12, and 24 mm) of chopped carbon fibers were pneumatically dispersed and uniformly mixed into the cement with a 1% weight proportion. Then the CFRM and CFRC specimens were made for static and dynamic tests. The compressive and flexural strengths of the specimens were determined by using the standard ASTM C39/C 39M and ASTM C 293-02, respectively. Meanwhile, a free-fall impact test was done according to ACI 544.2R-89, which was used to test the impact resistances of the specimens under different impact energies. The CFRM and CFRC with a length of 6 mm exhibit maximum compressive strength. Both flexural and free-fall impact test results show that the 24 mm CFRM and CFRC enhances their maximum flexural strength and impact numbers more than the other lengths of CFRM, CFRC, and the benchmark specimens. After impact tests, the failure specimens were observed in a high-resolution optical microscope, to identify whether the failure mode is slippage or rupture of the carbon fiber. Finally, a blast wave explosion test was conducted to verify that the blast wave resistance of the 24 mm CFRC specimen was better than the 12 mm CFRC and benchmark specimens.

Strain Measurement in the Steel Shell Surface Impacted by a Falling Ball

2014 ◽  
Vol 548-549 ◽  
pp. 401-405
Author(s):  
Wei Liu ◽  
Jie Song ◽  
Hua Guan ◽  
Xiao Han ◽  
Jian Zhong Wu ◽  
...  
Keyword(s):  
Impact Test ◽  
Bridge Circuit ◽  
Time History ◽  
Wheatstone Bridge ◽  
Free Fall ◽  
Test Method ◽  
Steel Shell ◽  
Maximum Strain ◽  
Shell Surface ◽  
The Impact

In order to study the maximum strain of steel shell surface under the impact of a falling ball, a thin shell model and the strain time history curves of impact are achieved by ANSYS/LS-DYNA. A deformation behavior of the shell was calibrated from the test which uses a ball free fall and some resistance strain gauges pasted to the inner surface of an iron shell box. The gauges are connected as inputs to a Wheatstone bridge circuit and an Oscilloscope is used to observe the output. The results show the impact test and ANSYS/LS-DYNA simulation results are smoothly consistent with the strain of the test at the maximum strain amplitude of the model, and the maximum difference is 9.5%. Accurate results can be achieved by combining the test method and the simulation approach as an industrial application.

The Application of CFD to Underpin the Design of Gas Turbine Pre-Swirl Systems

2006 ◽  
Author(s):  
G. D. Snowsill ◽  
C. Young
Keyword(s):  
Gas Turbine ◽  
Computation Time ◽  
Computational Time ◽  
Computationally Efficient ◽  
Cooling Systems ◽  
Turbine Cooling ◽  
Secondary Systems ◽  
Set Up ◽  
Cooling Air ◽  
The Impact

The technique of pre-swirling cooling air to reduce its relative total temperature, as felt by rotating components, is well established. It is important to optimise the design of such systems in order to achieve maximum cooling effectiveness and to minimise the impact on cycle efficiency. Traditionally, these cooling systems have been developed by a combination of experimental investigation and careful evolution. However, more recently it has become practical to apply CFD to such problems. The nature of gas turbine cooling systems generally mandates the presence of discrete features on both static and rotating components, so that a fully rigorous analysis would need to be both 3D and unsteady, with the sub-domains adjacent to static and rotating surfaces solved in an appropriate frame of reference, together with a suitable interfacing procedure to communicate the evolving solution between each sub-domain. Such analyses are challenging for current CFD codes, both in terms of computation time and numerical stability. The present work explores the various options that are available to make such computations more practical and hence more accessible to the secondary systems modelling community. Significant reductions in set-up time can be achieved by adopting unstructured calculational meshes, although this may be at the expense of some loss of accuracy and increase in computational time relative to structured meshes. In the present work, an attempt has been made to quantify the effect of these choices. Depending on the configuration of the system under investigation, it may be permissible to ignore the unsteady interactions and to model the system using the more computationally efficient multiple reference frame (MRF) approach. Guidelines are proposed for assessing the likely impact of these simplifications on the results obtained.

Numerical Simulation of Aluminum Alloy Wheel 13° Impact Test Based on Abaqus

2012 ◽  
Vol 215-216 ◽  
pp. 1191-1196 ◽  
Author(s):  
Xiao Ming Yuan ◽  
Li Jie Zhang ◽  
Xin Ying Chen ◽  
Bing Du ◽  
Bao Hua Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Aluminum Alloy ◽  
Finite Element Model ◽  
Impact Test ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Experimental Result ◽  
Alloy Wheel ◽  
The Impact ◽  
The Finite Element Model

In order to predict the result of impact test in the design phase and reduce the experimental times, which can save cost and shorten development cycle, a finite element model of aluminum alloy wheel 13-degree impact test is established based on Abaqus. All mechanical parts such as the standard impact block, the assembly of the wheel and the tire, the support and bolts are included in the finite element model. The predicted result of finite element analysis and the experimental result agree very well shows the finite element model is correct. The equivalent plastic strain value was also put forward as fracture criterion for the wheel in the impact test which realizes the transition from the qualitative analysis to the quantitative analysis in the development process of aluminum alloy wheel.

scholarly journals Respon Helmet Sepeda Type BMX Material Polymeric Foam Diperkuat Serbuk Tandan Kosong Kelapa Sawit Terhadap Beban Impak Metode Jatuh Bebas

2018 ◽  
Vol 1 (1) ◽  
pp. 109-116
Author(s):  
Mahadi Mahadi
Keyword(s):  
Impact Test ◽  
Unsaturated Polyester ◽  
Free Fall ◽  
Bicycle Helmet ◽  
Foam Material ◽  
Matrix Resin ◽  
Test Rig ◽  
Polymeric Foam ◽  
Chopped Strand Mat ◽  
The Impact

Pengujian impak standar pada helmet sepeda diperlukan untuk mengetahui respon tegangan pada helmet akibat efek rambatan gelombang regangan dengan laju rambatan gelombang yang tinggi. Tujuan dari penelitian ini adalah untuk mengetahui berapa besar energi yang dapat diserap oleh helmet sepeda bila diberi beban impak. Penelitian dilakukan terhadap helmet sepeda type BMX dengan formasi saluran udara (wind channel) tertentu yang terbuat dari material polymeric foam diperkuat serbuk tandan kosong kelapa sawit (TKKS) mesh40. Struktur geometri helmet uji terdiri dari lapisan luar (shell) terbuat dari material matrix resin unsaturated Polyester BQTN-157EX dan penguat serat glass chopped strand mat 300. Lapisan dalam (liner) adalah material polymeric foam menggunakan matrix resin unsaturated Polyester BQTN-157EX, penguat serbuk TKKS mesh40, Blowing AgentPolyurethane dan katalis Methyl Ethyl Keton Peroksida (MEKPO). Nilai dari sifat mekanik polymeric foam adalah tegangan tarik (σt) 1,17 MPa, tegangan tekan (σc) 0,51 MPa, tegangan bending (σb) 3,94 MPa, modulus elastisitas (E) 37,97 Mpa dan density (ρ) 193 (kg/m3). Metode impak yang dilakukan adalah jatuh bebas standar Consumer Product Safety Commision (CPSC). Helmet sepeda yang diuji adalah hasil dari desain standar Bicycle Helmet Safety Institute (BHSI) yang mempunyai dimensi panjang 264 mm, lebar 184 mm, dan tinggi 154 mm dengan lingkar kepala 580 mm. Massa test rig pada alat uji yang digunakan sebesar 5 kg dan massa helmet sepeda hasil cetakan bervariasi 328 s/d 451gr. Pengujian impak jatuh bebas dilakukan pada 18 sampel helmet ketebalan 10 mm dan 20 mm pada ketinggian 1,5 m dengan menggunakan flat anvil. Hasil uji impak pada parameter Gaya impak terbesar (Fi ), Energi Impak terbesar (Ei), Impuls (I), Tegangan Impak terbesar (σi) adalah 241,55 N, 283,77 J, 6,28 Ns, 2,02 MPa untuk tebal 10 mm dan 226,80 N, 360,23 J, 6,80 Ns, 1,90 MPa untuk tebal 20 mm.   Standard impact testing on bicycle helmets is needed to determine the  response on the helmet voltage due to the effect of strain wave propagation with a high a rate of wave propagation. The purpose of this reseach is to find out how much energy can be absorbed by the bicycle helmet if it is given an impact load. The reseach  was conducted on BMX type bicycle helmet with a certain wind channels formation made of polymeric foam material strengthened by the powder of oil palm empty bunches (TKKS) mesh40. The geometry structure of the tested helmet consists of a shell made by the material of unsaturated Polyester BQTN-157EX resin and the fiber strengthener of glass chopped strand mat 300. The inner layer (liner) is a polymeric foam material using unsaturated Polyester BQTN-157EX resin matrix, TKKS powder strengthener Mesh40, Blowing Agent Polyurethane and catalyst Methyl Ethyl Ketone Peroxide (MEKPO). The characterizatons of the polymeric foam mechanical are tensile stress (σt) 1.17 MPa, compression stress (σc) 0.51 MPa, bending stress (σb) 3.94 MPa, elastic modulus (E) 37.97 Mpa and density (ρ ) 193 (kg / m3). The impact method was using the standard free fall of the Consumer Product Safety Commission (CPSC). The bicycle helmet tested is the result of the standard Bicycle Helmet Safety Institute (BHSI) design that has dimensions of 264 mm in length, 184 mm in width, and 154 mm in height with a head circumference of 580 mm. The mass of the test rig on the test equipment used was 5 kg and the helmet mass of the printed bicycle varied from 328 to 451gr. The free fall impact test was carried out on 18 helmet samples thickness of 10 mm and 20 mm at an altitude of 1.5 m using anvil flat. The impact test results in the parameters of the largest impact force (Fi), the largest impact energy (Ei), Impuls (I), the largest impact voltage (σi) are 241.55 N, 283.77 J, 6.28 Ns, 2.02 MPa for 10 mm and 226.80 N thickness, 360.23 J, 6.80 Ns, 1.90 MPa for 20 mm thickness.

scholarly journals Desain Alat Uji Impak Jatuh Bebas Untuk Pengujian Baja Struktur

2020 ◽  
Vol 1 (2) ◽  
pp. 29-37
Author(s):  
Dailami Dailami ◽  
Samsul Bahri ◽  
Hamdani Hamdani
Keyword(s):  
Structural Steel ◽  
Impact Test ◽  
Steel Structure ◽  
Steel Structures ◽  
Free Fall ◽  
Operating Conditions ◽  
Impact Testing ◽  
Test Tool ◽  
Price Momentum ◽  
The Impact

Abstract Impact testing is a test to measure material resistance to shock loads (dynamic). Impact testing simulates the material operating conditions often encountered when the load does not always occur slowly but rather comes suddenly. The impact test equipment to be designed in this study is a free-fall impact test. This impact test tool utilizes the mass of the object and the force of gravity. This test aims to analyze the effect of free fall impact loading on steel structures dropped from 1.5m height. The steps taken in this study include testing and data collection to determine the energy absorbed, the impact price, momentum, impulse and toughness in steel structure material when given a shock load. In this free fall impact test, weight load is at (m) = 2.4 kg with an altitude distance of (h) = 1.5m. The test results showed that the maximum absorbable energy of structural steel is at (E) = 352.94 J, the maximum impact value of structural steel at (HI) = 8.82 J / mm2, the maximum momentum of structural steel at (M) 39.04 kg.m / s and the maximum implant steel structure at (I) 39.04 Ns. Mechanical behaviour is indicated by the bending of the specimen due to impact collision (striker) when testing is done. Keywords: Free-fall impact, Structure steel __________________________ Abstrak Pengujian impak merupakan suatu pengujian untuk mengukur ketahanan bahan terhadap beban kejut (dinamis). Pengujian impak mensimulasikan kondisi operasi material yang sering ditemui dimana beban tidak selamanya terjadi secara perlahan-lahan melainkan datang secara tiba-tiba. Alat uji impak yang akan dirancang dalam penelitian ini merupakan alat uji impak jatuh bebas. Alat uji impak ini memanfaatkan massa benda serta gaya gravitasi. Pengujian ini bertujuan untuk menganalisa pengaruh pembebanan impak jatuh bebas pada baja struktur yang dijatuhkan dari ke tinggian 1,5m. Langkah yang dilakukan dalam penelitian ini meliputi pengujian dan pengambilan data untuk mengetahui energi yang diserap, harga impak, momentum, implus dan ketangguhan pada material baja struktur saat diberi beban kejut. Pada pengujian impak jatuh bebas ini, mempunyai jarak dan berat beban yaitu pada beban (m) = 2,4 kg dengan jarak ketinggian (h) = 1,5m . Dari hasil pengujian yang diperoleh energi yang diserap maksimum baja struktur (E) = 352,94 J, harga impak maksimum baja struktur (HI) = 8,82 J/mm2, momentum maksimum baja struktur (M) 39,04 kg.m/s dan implus maksimum baja struktur (I) 39,04 Ns. Perilaku mekanis ditunjukkan dengan terjadinya pembengkokan pada spesimen akibat benturan Beban (striker) saat pengujian dilakukan. Kata Kunci: Impak jatuh bebas, Baja struktur __________________________

scholarly journals A critical review of FEM models to simulate the nano-impact test on PVD coatings

2018 ◽  
Vol 188 ◽  
pp. 04017
Author(s):  
Georgios Skordaris ◽  
Konstantinos Bouzakis ◽  
Paschalis Charalampous
Keyword(s):  
Finite Element ◽  
Impact Test ◽  
Fem Simulation ◽  
Numerical Procedure ◽  
Analytical Description ◽  
Computational Time ◽  
Pvd Coatings ◽  
3D Fem ◽  
Fem Model ◽  
Element Discretization

Nano-impact test is a reliable method for assessing the brittleness of PVD coatings with mono- or multi-layer structures. For the analytical description of this test, a 3D-FEM Finite Element Method (FEM) model and an axis-symmetrical one were developed using the ANSYS LS-DYNA software. The axis-symmetrical FEM simulation of the nano-impact test can lead to a significantly reduced computational time compared to a 3D-FEM model and increased result's accuracy due to the denser finite element discretization network. In order to create an axissymmetrical model, it was necessary to replace the cube corner indenter by an equivalent conical one with axis-symmetrical geometry. Results obtained by the developed FEM models simulating the nano-impact test on PVD coatings with various structures were compared with experimental ones. Taking into account the sufficient convergence between them as well as the reduced calculation time only in the case of an axis-symmetrical model, the latter introduced numerical procedure can be effectively employed to monitor the effect of various coating structures on their brittleness.

A Study on Reduction of Friction in Impact Compressive Test Based on the Split Hopkinson Pressure Bar Method by Using a Hollow Specimen

2014 ◽  
Vol 566 ◽  
pp. 548-553 ◽  
Author(s):  
Nobuhiko Kii ◽  
Takeshi Iwamoto ◽  
Alexis Rusinek ◽  
Tomasz Jankowiak
Keyword(s):  
Impact Test ◽  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Hopkinson Pressure Bar ◽  
Compressive Test ◽  
Friction Effect ◽  
Wide Range ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
The Impact

The split Hopkinson pressure bar (SHPB) technique is widely-used to describe the impact compressive behavior of different materials including metals. During the impact test, the specimen deforms in a wide range of impact strain rate from 102 to 104 s-1. It is a reason why the method is studied for many years even though the structure of the apparatus based on the SHPB is simple. Actually, the cylindrical specimens are widely used for a compressive test and it is clearly seen that stress measured by the test includes the increment of stress (an error) derived by friction effect between a specimen and pressure bars. Therefore, it is important that the measured stress should indicate similar value as the proper stress of the material by reducing friction effect during not only quasi-static but also the impact test. Various attempts to reduce a friction effect in past have been conducted. A method to reduce friction effect is in general a use of lubricants. However, it is ineffective because it can be considered that this method contributes to an attenuation of the stress wave for obtaining the stress-strain curve under impact loading. Thus, rise time of waves obtained by the experiment becomes longer compared with a case not to use lubricants. Recently, a study can be found using a ring specimen, however, the determined thickness of the specimen is quite thin and it can be considered that a buckling effect cannot be vanished. In this study, a use of hollow specimen is suggested to solve the problem related to reduce the friction effect by decreasing a contact area between a specimen and pressure bars instead of a cylindrical specimen. The compressive experiments at various strain rates are conducted by using a hollow specimen.

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