scholarly journals Impact Analysis of Transition between Semi-Rigid and Rigid Barriers Using Simulations

2021 ◽  
Vol 21 (6) ◽  
pp. 9-19
Author(s):  
Kyoungju Kim ◽  
Hyunung Bae ◽  
Jongmin Kim

Transition is a type of barrier that connects other barriers with different grades and shapes. Even if each barrier satisfies the performance, it may not be satisfied in transition. Therefore, collision safety requires a special design and examination. In this study, we investigated national and foreign standards and situations for the proper configuration of the transition and analyzed the impact behavior of the general transition using impact simulations. We developed a transition system that could ensure the stable performance of various grades by analyzing the behavior and confirmed based on the full-scale crash test (SB2 level).

2000 ◽  
Author(s):  
Krishnakanth Aekbote ◽  
Srinivasan Sundararajan ◽  
Joseph A. Prater ◽  
Joe E. Abramczyk

Abstract A sled based test method for simulating full-scale EEVC (European) side impact crash test is described in this paper. Both the dummy (Eurosid-1) and vehicle structural responses were simulated, and validated with the full-scale crash tests. The effect of various structural configurations such as foam filled structures, material changes, rocker and b-pillar reinforcements, advanced door design concepts, on vehicle performance can be evaluated using this methodology at the early stages of design. In this approach, an actual EEVC honeycomb barrier and a vehicle body-in-white with doors were used. The under-hood components (engine, transmission, radiator, etc.), tires, and the front/rear suspensions were not included in the vehicle assembly, but they were replaced by lumped masses (by adding weight) in the front and rear of the vehicle, to maintain the overall vehicle weight. The vehicle was mounted on the sled by means of a supporting frame at the front/rear suspension attachments, and was allowed to translate in the impact direction only. At the start of the simulation, an instrumented Eurosid-1 dummy was seated inside the vehicle, while maintaining the same h-point location, chest angle, and door-to-dummy lateral distance, as in a full-scale crash test. The EEVC honeycomb barrier was mounted on another sled, and care was taken to ensure that weight, and the relative impact location to the vehicle, was maintained the same as in full-scale crash test. The Barrier impacted the stationary vehicle at an initial velocity of approx. 30 mph. The MDB and the vehicle were allowed to slide for about 20 inches from contact, before they were brought to rest. Accelerometers were mounted on the door inner sheet metal and b-pillar, rocker, seat cross-members, seats, and non-struck side rocker. The Barrier was instrumented with six load cells to monitor the impact force at different sections, and an accelerometer for deceleration measurement. The dummy, vehicle, and the Barrier responses showed good correlation when compared to full-scale crash tests. The test methodology was also used in assessing the performance/crashworthiness of various sub-system designs of the side structure (A-pillar, B-pillar, door, rocker, seat cross-members, etc.) of a passenger car. This paper concerns itself with the development and validation of the test methodology only, as the study of various side structure designs and evaluations are beyond the scope of this paper.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3554
Author(s):  
Robert Böhm ◽  
Andreas Hornig ◽  
Tony Weber ◽  
Bernd Grüber ◽  
Maik Gude

The impact behavior of carbon fiber epoxy bumper brackets reinforced with 2D biaxial and 2D triaxial braids was experimentally and numerically analyzed. For this purpose, a phenomenological damage model was modified and implemented as a user material in ABAQUS. It was hypothesized that all input parameters could be determined from a suitable high-speed test program. Therefore, novel impact test device was designed, developed and integrated into a drop tower. Drop tower tests with different impactor masses and impact velocities at different bumper bracket configurations were conducted to compare the numerically predicted deformation and damage behavior with experimental evidence. Good correlations between simulations and tests were found, both for the global structural deformation, including fracture, and local damage entities in the impact zone. It was proven that the developed phenomenological damage models can be fully applied for present-day industrial problems.


Author(s):  
Nathan Schulz ◽  
Chiara Silvestri Dobrovolny ◽  
Stefan Hurlebaus ◽  
Harika Reddy Prodduturu ◽  
Dusty R. Arrington ◽  
...  

Abstract The manual for assessing safety hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation. A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the flail space model (FSM) in a full-scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event. Additionally, a finite element (FE) model was developed and calibrated against the full-scale crash test. The calibrated model can be used to perform parametric simulations with different testing conditions. Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.


Author(s):  
Chiara Silvestri Dobrovolny ◽  
Harika Reddy Prodduturu ◽  
Dusty R. Arrington ◽  
Nathan Schulz ◽  
Stefan Hurlebaus ◽  
...  

The Manual for Assessing Safety Hardware (MASH) defines crash tests to assess the impact performance of highway safety features in frontal and oblique impact events. Within MASH, the risk of injury to the occupant is assessed based on a “flail-space” model that estimates the average deceleration that an unrestrained occupant would experience when contacting the vehicle interior in a MASH crash test and uses the parameter as a surrogate for injury risk. MASH occupant risk criteria, however, are considered conservative in their nature, due to the fact that they are based on unrestrained occupant accelerations. Therefore, there is potential for increasing the maximum limits dictated in MASH for occupant risk evaluation. A frontal full-scale vehicle impact was performed with inclusion of an instrumented anthropomorphic test device (ATD). The scope of this study was to investigate the performance of the Flail Space Model in a full scale crash test compared to the instrumented ATD recorded forces which can more accurately predict the occupant response during a collision event. Results obtained through this research will be considered for better correlation between vehicle accelerations and occupant injury. This becomes extremely important for designing and evaluating barrier systems that must fit within geometrical site constraints, which do not provide adequate length to redirect test vehicles according to MASH conservative evaluation criteria.


Author(s):  
Chuck A. Plaxico ◽  
Malcolm H. Ray ◽  
Kamarajugadda Hiranmayee

Several types of strong-post W-beam guardrails are used in the United States. Usually the only difference between one type of strong-post W-beam guardrail and another is the choice of post and block-out types. The impact performance of two very similar strong-post W-beam guardrails are compared—the G4(2W), which uses a 150×200 mm wood post and the G4(1W), which uses a 200×200 mm wood post. Although G4(2W) is used in numerous states, G4(1W) is now common only in the state of Iowa. The performance of the two guardrails has been presumed equal, but only one full-scale crash test has been performed on G4(1W) and that was over 30 years ago, using a now-obsolete test vehicle. The nonlinear finite element analysis program LS-DYNA was used to evaluate the crashworthiness of the two guardrails. The G4(2W) guardrail model was validated with the results of a full-scale crash test. A model of the G4(1W) guardrail system was developed, and the deflection, vehicle redirection, and occupant risk factors of the two guardrails were compared. The impact performance of the two guardrails was quantitatively compared using standard techniques. The analysis results indicate similar collision performance for G4(1W) and G4(2W) and show that both satisfy NCHRP Report 350 Test 3-11 safety performance requirements.


2011 ◽  
Vol 110-116 ◽  
pp. 632-636
Author(s):  
K. Pazhanivel ◽  
G.B. Bhaskar ◽  
S. Arunachalam ◽  
V. Hariharan ◽  
A. Elayaperumal

Composite materials have a number of properties that make them attractive for use in aerospace applications. The impact behavior of fiber reinforced composite materials is much more complex than conventional metallic structures due to a number of different failure modes on the inter laminar and intra laminar level. The aim of this study is to investigate the effects of temperature and thermal residual stresses on the impact behavior and damage of glass/epoxy laminated composites. To this end, thermal stress analyses of the laminates with lay-ups [90/0/0/90] s, [90/0/45/45] s, [0/90/45/-45] s, [45/0/-45/90] s are carried out under different temperatures by using ANSYS software. Also, the impact analysis on the laminated composites was performed at the different range of impact energies under different temperatures. The specific energy values and impact parameters were obtained and compared for each type of specimens and temperatures.


2018 ◽  
Vol 917 ◽  
pp. 218-222 ◽  
Author(s):  
Sonika Sahu ◽  
Mohd Zahid Ansari ◽  
Chong Du Cho

Numerical simulation is performed to study the deformation and failure modes of Al 1100 plate of 2.4 mm thickness, subjected to low-velocity impact. Blunt and hemispherical nose shaped impactors are used in this study. The quasi-static tensile test is performed at a strain rate of 0.01/s to obtain the Johnson-Cook material parameters which are used in numerical simulation software, ABAQUS/CAE to perform impact analysis. Mesh convergence study is carried out to decide the appropriate number of elements for numerical analysis. The impact behavior of Al 1100 plate for each impactor shapes are studied at 22 J impact energy. Result indicate that increased in the nose radius of impactor will increase the amount of deformation energy for aluminium plate.


Author(s):  
Steven W. Kirkpatrick ◽  
Joseph M. Munaretto ◽  
Virginia Phan ◽  
Robert A. MacNeill

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Much of this research has been performed using detailed nonlinear finite element analyses supported by full scale impact testing. This use of detailed simulation methodologies has significantly improved our understanding of the tank impact behaviors and puncture safety. However, the performance of the detailed analyses or full scale testing can require significant computer or financial resources to evaluate a wide range of impact scenarios. This paper describes the development of analytical models that can predict the impact and puncture behavior of a pressurized railroad tank car. The methodology applied is to first develop a model that can predict the force-deflection behavior obtained from a general impact at any point on the tank. Separately, a characteristic puncture force is determined as a function of the tank geometry, impactor geometry, and impact conditions. Combined, these models can be applied to predict the impact and puncture behavior of the tank.


Author(s):  
Jin Sung Kim ◽  
Hyun Seung Jung ◽  
Tae Soo Kwon ◽  
Won Mok Choi ◽  
Seung Wan Son

KRRI (Korea Railroad Research Institute) has successfully performed several tens of impact tests of crash parts for a railway vehicles. Full-scale crash testing facilities were newly established including a crash barrier, dynamic load cell, high speed DAS (Data Acquisition System), a laser displacement sensor, dummies, a motor car and etc. This paper introduces series of impact test results using full-scale crash testing facilities. The impact test for railway vehicles consists of three categories, i.e. single item tests, module tests and crash structure tests. For single item tests, expansion tubes, composite tubes, collapsible tubes and etc. were tested. For module tests, a crash test of a light collision safety device with an expansion tube and triggering mechanism was performed. For crash structure tests, several full-scale crash tests were performed including front-end and cab structures with or without dummies. The crash testing equipment developed will be able to evaluate the occupant safety as well as the structural crashworthiness of a train.


Author(s):  
Zachery E. Heller ◽  
Joseph Wyatt ◽  
Jeffery C. Wolchok

An in-vitro system was developed to mimic the impact deceleration and strain associated with concussive injuries. Similar in concept to a full scale crash test, the bench top concussive bioreactor can deliver decelerations from 0–250 g and biaxial strains from 5–25% to cells in culture. We are not aware of another system like this. From cellular testing, an injury threshold of 100g combined with 10% strain was identified. These values appear consistent with human brain injury data.


Sign in / Sign up

Export Citation Format

Share Document