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.

EFFECT OF RELATIVE DENSITY AND VELOCITY TOWARDS DYNAMIC RESPONSE OF METAL FOAM

2015 ◽  
Vol 76 (9) ◽  
Author(s):  
Mohd Azman Y. ◽  
Juri S. ◽  
Hazran H. ◽  
NorHafiez M. N. ◽  
Dong R.
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Theoretical Prediction ◽  
Relative Density ◽  
Impact Velocity ◽  
Impact Test ◽  
Metal Foam ◽  
Element Analysis ◽  
Static Tests ◽  
The Impact

Dynamic response of ALPORAS aluminium foam has been investigated experimentally and numerically. The dynamic response is quantified by the force produced as the foam deforms as a function of time. Quasi-static tests are conducted to determine the quasi-static properties of the foam. In the impact test, the aluminium foams are fired towards a rigid load-cell and the force signals developed are recorded. Experimental dynamic stress is also compared with theoretical prediction using existing theory. Finite element model is constructed using LS-DYNA to simulate the impact test. Results from the experiment, finite element analysis and theoretical prediction are in acceptable agreement. Finally, parametric studies have been conducted using the verified model to investigate the effect of impact velocity and relative density towards the dynamic response of the foam projectile. It is found that the dynamic response of the foam is more sensitive towards impact velocity as compare with the foam relative density.

Numerical Analysis of Impact Velocity on the Responses of Adhesively Bonded Steel Butt Joint with Material Properties

2013 ◽  
Vol 644 ◽  
pp. 193-196 ◽  
Author(s):  
Min You ◽  
Kai Liu ◽  
Hai Zhou Yu ◽  
Ling Wu ◽  
Mei Li
Keyword(s):  
Impact Velocity ◽  
Material Properties ◽  
Impact Test ◽  
Failure Time ◽  
Butt Joint ◽  
The Finite Element Method ◽  
Adhesively Bonded ◽  
Izod Impact ◽  
The Impact ◽  
Peak Value

The effect of the impact velocity on the responses of the adhesively bonded steel butt joint during Izod impact test and the failure procedure is studied using the finite element method software ABAQUS. The results obtained show that the failure time of the element becomes little shorter when the impact velocity increased from 3.2 m/s to 10.2 m/s. The peak value of the Seqv in element 1 increases first and then decreased when the impact velocity reached 4.2 m/s. When the impact velocity is higher than 6.2 m/s, the peak value of the Seqv increased again as the impact velocity increased until 10.2 m/s. It is recommended that the impact velocity of 3.2 m/s or 5.2 m/s is suitable for Izod impact test for the adhesively bonded steel butt joint.

scholarly journals Parametric Study on the Free-Fall Water Entry of a Sphere by Using the RANS Method

2019 ◽  
Vol 7 (5) ◽  
pp. 122
Author(s):  
Pengyao Yu ◽  
Cong Shen ◽  
Chunbo Zhen ◽  
Haoyun Tang ◽  
Tianlin Wang
Keyword(s):  
Impact Velocity ◽  
Impact Force ◽  
Free Fall ◽  
Water Entry ◽  
Time Step ◽  
Measuring Device ◽  
Mesh Density ◽  
The Impact ◽  
Peak Value ◽  
Rans Method

Motivated by the application of water-entry problems in the air-drop deployment of a spherical oceanographic measuring device, the free-fall water entry of a sphere was numerically investigated by using the transient Reynolds-averaged Navier–Stokes (RANS) method. A convergence study was carried out, which accounts for the mesh density and time-step independence. The present model was validated by the comparison of non-dimensional impact force with previous experimental and numerical results. Effects of parameters, such as impact velocity, radius, and mass of the sphere on the impact force and the acceleration of the sphere, are discussed. It is found that the peak value of the non-dimensional impact force is independent of the impact velocity and the radius of the sphere, while it depends on the mass of the sphere. By fitting the relationship between the peak value of the non-dimensional impact force and the non-dimensional mass, simplified formulas for the prediction of peak values of the impact force and the acceleration were achieved, which will be useful in the design of the spherical oceanographic measuring device.

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 Sonic and Impact Test for Structural Assessment of Historical Masonry

2019 ◽  
Vol 9 (23) ◽  
pp. 5148 ◽  
Author(s):  
Alessandro Grazzini
Keyword(s):  
Impact Test ◽  
Structural Parameters ◽  
Historical Masonry ◽  
2016 Amatrice Earthquake ◽  
The Impact ◽  
Santa Maria ◽  
Non Destructive ◽  
Non Destructive Techniques

Diagnostics is a very important tool of knowledge in the field of historical buildings. In particular, non-destructive techniques allow to deepen the study of the mechanical characteristics of the historical walls without compromising the artistic value of the monumental building. A case study of the use of sonic and impact tests was described, performed using the same instrumented hammer, for the characterization of the masonry walls at the Sanctuary of Santa Maria delle Grazie at Varoni, one of the churches damaged in the 2016 Amatrice earthquake. Sonic tests showed the presence of a discontinous masonry texture, as well as confirming the ineffectiveness of the strengthening work made by injections of lime mortar. The impact test allowed us to obtain the elastic modulus of the omogeneous stones of the masonry. The results obtained from the non-destructive techniques were confirmed by the flat jacks test carried out on the building, confirming the great potential of the non-destructive diagnostics suitable for analyzing important structural parameters without affecting the preservation of historical masonry structures.

scholarly journals Impact of Magnetically Treated Water on Compressive and Flexural Strength of Concrete

2021 ◽  
Vol 18 (3) ◽  
pp. 251-257
Author(s):  
K.O. Yusuf ◽  
T.D. Akpenpuun ◽  
S.O. David ◽  
C.H. Oluwayemi
Keyword(s):  
Impact Test ◽  
Coarse Aggregate ◽  
Testing Machine ◽  
Fine Aggregate ◽  
Treated Water ◽  
Universal Testing ◽  
Impact Tester ◽  
The Mean ◽  
Compressive And Flexural Strengths ◽  
The Impact

This study was conducted to determine the effect of Magnetically Treated Water (MTW) on compressive, flexural and impact  strengths of concrete. The compressive strength, flexural and impact test were determined using 100 mm cube, 100x100x500 mm, 100mm diameter and 64 mm high, respectively. MTW was produced by passing water through magnetic flux densities: 400(T1), 600(T2), 800(T3) and 997G(T4) as the treatments while Non-MTW (NMTW, T0 as control). The ratio of cement, fine aggregate and coarse aggregate was 1:2:4 and curing duration for the concretes were 7, 14, 21 and 28 days. Universal Testing Machine was used to determine the compressive and flexural strengths while drop weighing impact tester was used for determining the impact strength of the concrete. The mean forces at peak to break the concrete cured for 28 days for T0, T1, T2, T3 and T4 were 106.79, 121.25, 114.15, 107.06 and 196.68 kN, while the compressive strengths were 10.68, 12.13, 11.42, 10.71 and 19.67 Nmm-2, respectively. The maximum compressive, flexural and impact strengths of the concrete were 84.17, 22.37 and 96.93%, respectively. The effect of MTW was statistically significant on compressive, flexural and impact strengths and is recommended for use.

scholarly journals Load Characteristics in Taylor Impact Test on Projectiles with Various Nose Shapes

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 713
Author(s):  
Jun-Cheng Li ◽  
Gang Chen ◽  
Feng-Lei Huang ◽  
Yong-Gang Lu
Keyword(s):  
Impact Velocity ◽  
Impact Analysis ◽  
Impact Test ◽  
Impact Load ◽  
Loading Test ◽  
Impact Theory ◽  
Nose Shape ◽  
Taylor Impact ◽  
Taylor Impact Test ◽  
The Impact

This study focused on the impact load produced by a projectile and its potential application in the Taylor impact test. Taylor impact tests were designed and carried out for projectiles with four types of nose shapes, and the impact deformation characteristics and variation of the impact load as a function of the nose shape and impact velocity were studied. The overall high g loading experienced by the projectile body during the impact was discussed, and based on classical Taylor impact theory, impact analysis models for the various nose-shape projectiles were established and the causes of the different impact load pulse shapes were analyzed. This study reveals that the nose shape has a significant effect on the impact load waveform and pulse duration characteristics, while the impact velocity primarily affects the peak value of the impact load. Thus, the loading of specific impact environments could be regulated by the projectile nose shape design and impact velocity control, and the impact load could be simulated. Research results support the assumption that the Taylor impact test can be applied to high g loading test.

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.

scholarly journals A Case Study of Brick Properties Manufacture in Bhaktapur

2019 ◽  
Vol 7 ◽  
pp. 27-33
Author(s):  
Shova Shrestha
Keyword(s):  
Specific Gravity ◽  
Water Absorption ◽  
Impact Test ◽  
Hardness Test ◽  
Color Appearance ◽  
Crushing Strength ◽  
Bright Color ◽  
Almost All ◽  
The Impact

Bricks are commonly used for construction of buildings structures. The main objective of this article is to present the case study on different properties of the bricks manufactured in Bhaktapur city. Sample specimens were collected and tested for crushing strength, water absorption, specific gravity, density, porosity, impact test, dimension test, hardness test, soundness test and color appearance test of bricks in the laboratory. The overall aim of this study is to determine, through extensive experimental investigation, the effect of different brick on strength, water absorption, density, hardness, impact, porosity, and crushing strength. After multiple tests, results regarding the properties of bricks included – water absorption varies from 8.80% to 23.93%, porosity varying from 19.28% to 53.99%, specific gravity varying from 2.19 to 4.00, density varying from 1549.77 kg/m3 to 2816.6kg/m3, and crushing strength varying from 7.83 MPa to 22.10 MPa. In hardness test, 15 out of 33 were found to be hard; while 13 out of 33 passed the impact test; and 18 out of 33 has metallic sound. For the good quality of brick, the brick should have bright color appearance but only 15 out of 33 samples carry bright color appearance. Regarding the dimensions, length varies from 212.00 mm to 242.00 mm, breadth varies from 96.00 mm to 115.00 mm and thickness varies from 48.80 mm to 63.00 mm. From this research, properties of almost all bricks are not as per Nepal Building Code. The bricks manufactured at present are being commercialized rather than maintaining the standards as per the code.

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