| 11. |
- Han, Y., et al.
(författare)
-
A study on chest injury mechanism and the effectiveness of a headform impact test for pedestrian chest protection from vehicle collisions
- 2012
-
Ingår i: Safety Science. - : Elsevier BV. - 0925-7535 .- 1879-1042. ; 50:5, s. 1304-1312
-
Tidskriftsartikel (refereegranskat)abstract
- This study was aimed at investigating the injury mechanism of pedestrian chests in collisions with passenger vehicles of various frontal shapes and examining the influence of the local structural stiffness on the chest injury risk by using the headform impact test at the chest contact area of the vehicle. Three simulations of vehicle to pedestrian collisions were conducted using three validated pedestrian finite element (FE) models of three pedestrian heights of 177 (AM50th), 165 and 150 cm and three FE vehicles,models representing a one-box vehicle, a minicar and a medium car. The validity of the vehicle models was evaluated by comparing the headform acceleration against the measured responses from headform impact tests. The chest impact kinematics and the injury mechanisms were analyzed in terms of the distribution of the von Mises stress of the ribcage and in terms of the chest deflections. The chest contact locations on the front panel and the bonnet top were identified in connection to the causation of rib fractures. The risk of rib fractures was predicted by using the von Mises stress distribution. The headform impact tests were carried out at the chest contact area on the front panel and bonnet to examine the safety performance with respect to pedestrian chest protection. In simulations of the one-box vehicle to pedestrian collisions, the chest was struck directly by the frontal structure at a high velocity and deformed substantially, since a shear force was generated by the stiff windshield frame. The acceleration of the headform was related to the rib deflections. The injury threshold of the ribcage deflection (42 mm) corresponded to the headform average acceleration of 68G. In the minicar collision, the chest was struck with the bonnet top and cowl area at a low velocity, and the deformation was small due to the distributed contact force between the chest and the bonnet top. Besides, the ribcage deformation was too small for bridging a relation between the headform accelerations and rib deflections. In the medium car collision, the deformation mode of the chest was similar to that in the minicar collision. The chest collided with the bonnet top at a low velocity and deformed uniformly. The deflection of the ribs had an observable correlation with the headform accelerations measured in the headform impact tests. The frontal shape of a vehicle has a large influence on a pedestrian's chest loadings, and the chest deformation depends on the size of the pedestrian and the stiffness of the vehicle. The one-box passenger vehicle causes a high chest injury risk. The headform impactor test can be utilized for the evaluation of the local stiffness of a vehicle's frontal structure. The reduction of the headform acceleration is an effective measure for pedestrian chest protection for specific shapes of vehicles by efficacy in modifying the local structural stiffness.
|
|
| 12. |
- Jiang, X., et al.
(författare)
-
An investigation of biomechanical mechanisms of occupant femur injuries under compression-bending load
- 2014
-
Ingår i: Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics. - 0459-1879. ; 46:3, s. 465-474
-
Tidskriftsartikel (refereegranskat)abstract
- Occupant femur fractures occur frequently under compression-bending load in the frontal crashes of passenger cars. In order to explore the injury mechanisms and tolerances of occupants' femur in this load condition, a finite element model of the lower extremity in the sitting posture was developed based on the anatomy of a 50th percentile male. Then the model was validated against two types of cadaver tests, including three-point dynamic bending test of the femur and the axial impact test on the knee-thigh complex. A study of femur fractures under compression-bending load has been carried out using an analytical model of the curved beam. Furthermore, six virtual tests were conducted using the validated finite element model. The results show that the location of bone fractures and the tolerance of the femur depend on both bending load and axial compression. With the increasing preload of the bending moment from 0 to 676 Nm, the femur fracture location was shift from the femoral neck to the shaft. Regarding the tests with fractures occurring in the femoral neck, the tolerance of the femur is between 285 and 296 Nm. For the other tests with fractures located in the femoral shaft, the tolerance of the femur is between 381 and 443 Nm. The results indicated that the femur fractures always occurred at the femoral neck in axial impact tests on the knee-thigh complex, but in real world car frontal impacts the femoral shaft fractures can be observed frequently.
|
|
| 13. |
|
|
| 14. |
- Malm, Annika, 1970, et al.
(författare)
-
The association of drinking water treatment and distribution network disturbances with Health Call Centre contacts for gastrointestinal illness symptoms
- 2013
-
Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 47:13, s. 4474-4484
-
Tidskriftsartikel (refereegranskat)abstract
- There are relatively few studies on the association between disturbances in drinking waterservices and symptoms of gastrointestinal (GI) illness. Health Call Centres data concerningGI illness may be a useful source of information. This study investigates if there is anincreased frequency of contacts with the Health Call Centre (HCC) concerning gastrointestinal symptoms at times when there is a risk of impaired water quality due to disturbances at water works or the distribution network. The study was conducted inGothenburg, a Swedish city with 0.5 million inhabitants with a surface water source ofdrinking water and two water works. All HCC contacts due to GI symptoms (diarrhoea,vomiting or abdominal pain) were recorded for a three-year period, including also sex, age,and geocoded location of residence. The number of contacts with the HCC in the affectedgeographical areas were recorded during eight periods of disturbances in the water works(e.g. short stops of chlorine dosing), six periods of large disturbances in the distributionnetwork (e.g. pumping station failure or pipe breaks with major consequences), and 818pipe break and leak repairs over a three-year period. For each period of disturbance theobserved number of calls was compared with the number of calls during a control periodwithout disturbances in the same geographical area. In total about 55, 000 calls to the HCCdue to GI symptoms were recorded over the three-year period, 35 per 1000 inhabitants andyear, but much higher (>200) for children
|
|
| 15. |
- Peng, Yong, et al.
(författare)
-
A study of pedestrian and bicyclist exposure to head injury in passenger car collisions based on accident data and simulations
- 2012
-
Ingår i: Safety Science. - : Elsevier BV. - 0925-7535 .- 1879-1042. ; 50:9, s. 1749-1759
-
Tidskriftsartikel (refereegranskat)abstract
- The objective was to assess head injury risks and kinematics of adult pedestrians and bicyclists in primary impact to the passenger cars and secondary impact to the ground using real world accident data and computer reconstructions of the accidents. For this purpose, a subsample of 402 pedestrians and 940 bicyclists from the GIDAS database, Germany, was used for the statistical analysis, from which 22 pedestrian and 18 bicyclist accidents were further selected for reconstruction. PC-Crash was used to calculate impact conditions, such as vehicle impact velocity, vehicle kinematic sequence, and thrown distance. These conditions were employed to identify the initial conditions in reconstruction in MADYMO program. A comparable analysis was conducted based on the results from accident analysis and computer reconstructions for the impact configurations and the resulting injury patterns of pedestrians and bicyclists in view of head injury risks. Differences in HIC, head-relative impact velocity, linear acceleration, maximum angular velocity and acceleration, contact force, thrown distance, Wrap Around Distance (WAD), and head contact time were evaluated. Injury risk curves were generated by using a logistic regression model for vehicle impact velocity. The results indicate that bicyclists suffered less severe injuries compared with severity of pedestrian injuries. In the selected samples, the AIS 2+ and AIS 3+ head injury risks for pedestrians are 50% probability at impact speed of 38.87 km/h and 54.39 km/h respectively, while for bicyclists at 53.66 km/h and 58.89 km/h respectively. The findings of high injury risks suggested that in the area with high frequency car-pedestrian accidents, the vehicle speed limit should be 40 km/h, while in the area with high frequency car-cyclist accidents the vehicle speed limit should be 50 km/h. (C) 2012 Elsevier Ltd. All rights reserved.
|
|
| 16. |
- Short, Tim, et al.
(författare)
-
Manufacturing, sustainability, ecodesign and risk : Lessons learned from a study of Swedish and English companies
- 2012
-
Ingår i: Journal of Cleaner Production. - : Elsevier. - 0959-6526 .- 1879-1786. ; 37, s. 342-352
-
Tidskriftsartikel (refereegranskat)abstract
- Previous research suggests that, despite a desire to introduce environmental concerns into New Product Design, many companies in the northwest of England have not done so. In order to understand more about why companies do or do not take on sustainability methodologies, an entirely new and rigorous approach was taken. This paper therefore presents the results of a questionnaire investigating the up-take of Eco/Sustainable Design in manufacturing companies in Sweden - a country that might be considered more environmentally progressive than the UK - and discusses them alongside the results of an identical questionnaire in the UK. The results are presented in the context of risk and risk aversion/management - in particular the risk associated with taking on board Design for Sustainability as a design method or a company strategy. It is found that there is no clear "winner" in sustainability between UK and Swedish engineering companies; there is encouraging news in both countries, with a desire to practice sustainability, but some that is not so good with the number of companies that actually implement relevant methodologies. It is apparent that there are still hindrances and perceived risks preventing companies taking sustainability fully on board, despite the recognition that sustainability is a "good thing"; the importance of the implementation of sustainability has not yet been fully grasped by industry and by those with the responsibility required to effect any changes.
|
|
| 17. |
- Wang, F., et al.
(författare)
-
Finite element analysis of human rib fracture under various impact loading conditions
- 2014
-
Ingår i: Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics. - 0459-1879. ; 46:2, s. 300-307
-
Tidskriftsartikel (refereegranskat)abstract
- This study aimed at investigating the mechanism of the human rib fracture under various impact loading conditions based on different failure models. For this purpose, a validated FE thorax model was utilized for analysis of the rib fractures. Based on the human anatomical structures, the human thorax FE model consists of ribs, vertebras, sternum, costal cartilages, internal organs, and soft tissues. Material properties used in this model were based on the published literature. The phenomenon of human rib fractures was simulated in different configurations, including structural experiments of single rib and human thorax frontal crash experiments with a cylinder impactor. Based on different rib fracture failure models in human injury biomechanics, the rib fractures from simulations were analyzed and compared with the impact responses obtained from all of the experiments from the literature. The simulation results with the FE model showed that the applicability of rib fracture failure model would depend on the loading conditions. It was proved that the FE model could be used in research of human rib fracture biomechanics under various impact loading conditions in vehicle traffic accidents.
|
|
| 18. |
- Adriani, O., et al.
(författare)
-
Measurements of cosmic-ray proton and helium spectra with the PAMELA calorimeter
- 2013
-
Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 51:2, s. 219-226
-
Tidskriftsartikel (refereegranskat)abstract
- We present a new measurement of the cosmic ray proton and helium spectra by the PAMELA experiment performed using the "thin" (in terms of nuclei interactions) sampling electromagnetic calorimeter. The described method, optimized by using Monte Carlo simulation, beam test and experimental data, allows the spectra to be measured up to 10 TeV, thus extending the PAMELA observational range based on the magnetic spectrometer measurement.
|
|
| 19. |
- Bagherbandi, Mohammad, et al.
(författare)
-
Recovery of Moho's undulations based on the Vening Meinesz-Moritz theory from satellite gravity gradiometry data : A simulation study
- 2012
-
Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 49:6, s. 1097-1111
-
Tidskriftsartikel (refereegranskat)abstract
- In the gravimetric approach to determine the Moho depth an isostatic hypothesis can be used. The Vening Meinesz-Moritz isostatic hypothesis is the recent theory for such a purpose. Here, this theory is further developed so that the satellite gravity gradiometry (SGG) data are used for recovering the Moho depth through a nonlinear integral inversion procedure. The kernels of its forward and inverse problems show that the inversion should be done in a larger area by 5 than the desired one to reduce the effect of the spatial truncation error of the integral formula. Our numerical study shows that the effect of this error on the recovered Moho depths can reach 6 km in Persia and it is very significant. The iterative Tikhonov regularization in a combination with either generalized cross validation or quasi-optimal criterion of estimating the regularization parameter seems to be suitable and the solution is semi-convergent up to the third iteration. Also the Moho depth recovered from the simulated SGG data will be more or less the same as that obtained from the terrestrial gravimetric data with a root mean square error of 2 km and they are statistically consistent.
|
|
| 20. |
|
|
