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.

Experimental Determination of Dynamic Characteristics of a Full Size Gas Turbine Tilting-Pad Journal Bearing by an Impact Test Method

1991 ◽  
Author(s):  
S. H. Chan ◽  
M. F. White
Keyword(s):  
Gas Turbine ◽  
Impact Test ◽  
Journal Bearing ◽  
Estimation Procedure ◽  
Response Spectra ◽  
Test Method ◽  
Full Size ◽  
Tilting Pad ◽  
Tilting Pad Journal Bearing ◽  
The Impact

Abstract Measurements have been taken on an experimental rotor-bearing test rig which consists of a full size gas turbine shaft supported by two five-pad tilting-pad journal bearings. The impact test method was applied by exciting one end of the shaft in-situ by means of a hammer blow. Impact forces and response displacements were collected and analysed with suitable corrections for runout effect. Averaged frequency response spectra thus obtained were used in a parameter estimation procedure to calculate the dynamic coefficients of the tested tilting-pad journal bearing. An analytical single degree-of-freedom model was employed and one of the input parameters in the mechanical model, the effective mass, was found to significantly influence the estimated results. The measured stiffness and damping coefficients are compared with results predicted by a bearing design program. Possible sources of discrepancies between experimental and theoretical results are discussed.

THE EFFECTIVENESS OF THE COMPONENT IMPACT TEST METHOD FOR THE SIDE IMPACT INJURY ASSESSMENT OF THE DOOR TRIM

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1766-1773
Author(s):  
YOUNGHAN YOUN ◽  
JEONG-SEO KOO
Keyword(s):  
Impact Test ◽  
Reaction Force ◽  
Design Guidelines ◽  
Test Method ◽  
Abdominal Injury ◽  
Side Impact ◽  
Crash Test ◽  
Conservation Of Energy ◽  
Absorption Energy ◽  
The Impact

The complete evaluation of the side vehicle structure and the occupant protection is only possible by means of the full scale side impact crash test. But, auto part manufacturers such as door trim makers can not conduct the test especially when the vehicle is under the developing process. The main objective of this study is to obtain the design guidelines by a simple component level impact test. The relationship between the target absorption energy and impactor speed were examined using the energy absorbed by the door trim. Since each different vehicle type required different energy levels on the door trim. A simple impact test method was developed to estimate abdominal injury by measuring reaction force of the impactor. The reaction force will be converted to a certain level of the energy by the proposed formula. The target of absorption energy for door trim only and the impact speed of simple impactor are derived theoretically based on the conservation of energy. With calculated speed of dummy and the effective mass of abdomen, the energy allocated in the abdomen area of door trim was calculated. The impactor speed can be calculated based on the equivalent energy of door trim absorbed during the full crash test. With the proposed design procedure for the door trim by a simple impact test method was demonstrated to evaluate the abdominal injury. This paper describes a study that was conducted to determine sensitivity of several design factors for reducing abdominal injury values using the matrix of orthogonal array method. In conclusion, with theoretical considerations and empirical test data, the main objective, standardization of door trim design using the simple impact test method was established.

A Study on Dynamic Characteristics of Hyper-Elastic Shock Programmer with Truncated Conical Shape

2013 ◽  
Vol 871 ◽  
pp. 240-246
Author(s):  
Tae Ho Yang ◽  
Young Shin Lee ◽  
Yoon Jae Kim ◽  
Tae Hyeong Kim ◽  
Chang Won Shul ◽  
...  
Keyword(s):  
Elastic Material ◽  
Impact Test ◽  
Time History ◽  
Material Model ◽  
Wave Shape ◽  
Time Duration ◽  
Conical Shape ◽  
Design Variables ◽  
Hyper Elastic ◽  
The Impact

Polyurethane (PU) S80A was used as the material of the elastomer of the shock programmer in this paper. To validate Ogden hyper-elastic material model in simulation, the small impact test was performed. As the comparison for the time history of the acceleration between the impact test and simulation was performed. Using the cylindrical shock programmer, the constant used in Ogden hyper-elastic material model was calculated. The wave shape of the acceleration was obtained with the noised sign. To clearly obtain the wave shape of the acceleration the cylindrical shock programmer, the truncated conical shock programmer was used. Using the Ogden hyper-elastic material model, design variables of the shock programmer with the truncated conical shape was studied. Using the shock programmer with truncated conical shape the range on the level and time duration of the acceleration in simulation was from 494.9 m/s2 to 10941 m/s2 and from 1.3 msec to 23.5 msec, respectively.

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 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 Impact Tests of UHSS Steel Welded Joints Using the Drop - Tower Impact Drop Method

2019 ◽  
Vol 19 (3) ◽  
pp. 19-31
Author(s):  
J. Dorożyński ◽  
J. Nowacki ◽  
A. Sajek
Keyword(s):  
Impact Strength ◽  
Welded Joints ◽  
Impact Test ◽  
Gma Welding ◽  
High Strength ◽  
Test Method ◽  
Drop Tower ◽  
Current Application ◽  
Impact Tests ◽  
The Impact

AbstractThe article characterizes the impact test method using Drop-Tower Impact Test with the registration of the value of force and energy of breaking. Based on sources, the possibilities and scope of the current application of this method were determined and the current state of knowledge on the results of these tests was reviewed. In order to determine the possibility of using the method in impact tests of high strength steel joints, investigations of hybrid PTA - GMA welding conditions on impact strength of joints of MART S1300QL steel were carried out. In particular, the influence of t8/5 cooling time on the impact strength of welded joints by the Drop - Tower Impact Test method was determined. It has been shown that the use of dropping machine with computer-based registration of breaking force and energy values was possible in the case of impact strength testing of UHSS welded joints and enabled precise analysis of the energy distribution dynamics absorbed by the tested.

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.

Force Reconstruction for Impact Tests

1991 ◽  
Vol 113 (2) ◽  
pp. 192-200 ◽  
Author(s):  
V. I. Bateman ◽  
T. G. Carne ◽  
D. L. Gregory ◽  
S. W. Attaway ◽  
H. R. Yoshimura
Keyword(s):  
Data Reduction ◽  
Impact Test ◽  
Time History ◽  
Scale Model ◽  
Accelerometer Data ◽  
Acceleration Technique ◽  
Reduction Techniques ◽  
Force Reconstruction ◽  
Reduction Methods ◽  
The Impact

Two force reconstruction techniques were used to evaluate the impact test of a scale model nuclear transportation cask dropped 30 ft. onto an unyielding target. The two techniques are: the sum of weighted acceleration technique (SWAT) and the deconvolution technique (DECON). A brief description and the calibration of the techniques as applied to the cask are presented. For the impact test, both techniques yielded very similar resultant forces and provided more accurate definition of the force-time history for the cask than is available from conventional data reduction methods. An applied moment, measurement previously unobtainable from conventional accelerometer data reduction techniques, was determined with SWAT. The angular velocity calculated with SWAT was verified with photometric measurements.

Impact Test Method for Automobile Plastic Tank Research and Equipment Development

2013 ◽  
Vol 456 ◽  
pp. 345-348
Author(s):  
Ling Long Wang ◽  
Tian Qiang Du ◽  
Wei Liu
Keyword(s):  
Simple Structure ◽  
Impact Test ◽  
Test Bench ◽  
Impact Resistance ◽  
Test Method ◽  
Test Rig ◽  
Equipment Development ◽  
Temperature Impact ◽  
The Difference ◽  
The Impact

The automobile fuel tank is an important component of the car, and it played an important role in the safety. Its one of the parts of car must be test in china and another place such as Europe before this parts used in a new car. In this article, the difference of requirement of low-temperature impact resistance is compared in GB18296-2001 and 70/221/EEC or ECE R34, then discuss the simple structure of pendulum for impact test according to GB18296-2001 and find it is not suitable for the impact test which required in 70/221/EEC.After that, designed an impact test rig meeting the requirements of the standard of GB18296-2001 and regulations of 70/221/EEC.The impact test bench is easy to operate, efficiency and safety.

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