| 1. |
- Amin, Khabat, et al.
(författare)
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Injury Reducing Effect of GSHP-Heated Pedestrian Paths
- 2024
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Ingår i: International Ground Source Heat Pump Association-Research Conference. ; , s. 227-235
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Konferensbidrag (refereegranskat)abstract
- In Sweden, falls amongst pedestrians during wintertime, due to slipping on ice and snow, is a costly and growing problem. Using data on pedestrian falls from four Swedish cities, the injury-reducing effect of heated surfaces was studied. The results indicate that heated surfaces have a significant injury-reducing effect especially in cities with more ice and snow. Currently, district heating is used as a heat source and at an increasing cost. By using GSHP systems as a heat source, the cost could be considerably lowered, and in this way secure the further use and expansion of heated pedestrian paths.
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| 2. |
- Andersson, Marianne, 1969, et al.
(författare)
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Characteristics of crashes involving injured children in side impacts
- 2011
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Ingår i: International Journal of Crashworthiness. - : Informa UK Limited. - 1358-8265 .- 1754-2111. ; 16:4, s. 365-373
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to define the crash characteristics of near-side impact crashes in which children seated in the rear rows are injured. The crash characteristics included the direction of force, heading angle, horizontal impact location, vertical impact location, extent of deformation and intrusion at the child occupant's seating position. Cases from in-depth crash investigation databases of the NASS-CDS (National Automotive Sampling System-Crashworthiness Data System), CIREN (Crash Injury Research and Engineering Network) and Chalmers University of Technology were reviewed. The principal direction of force was most frequently between 60° and 75°. The heading angle of the bullet vehicle was most commonly between 61° and 90°. The bullet vehicle hit the passenger compartment of the target vehicle, particularly the rear door. Often, one or both of the adjacent pillars to the rear door were involved, most commonly the B pillar. In 11 of 16 crashes, the car sill was not engaged. Most commonly, the deformation extent was into Zone 3 or more – about 40 cm – and the intrusion at the child's seating position was in the range 20–30 cm. This review of the crashes revealed differences between the current side impact test procedures and the actual side impact crashes in which children were injured.
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| 3. |
- Andersson, Marianne, 1969
(författare)
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Child Safety in Car Crashes
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Traffic related trauma is the most common cause of fatality and severe injury to children in developed countries. The majority of these fatalities and injuries are caused by frontal and side impacts. Researchers agree that the head is the most important body region to protect for all ages of children, while the thorax is equally important for older children. Injury epidemiology has shown that special attention is needed for the 3-year-olds in boosters and the 12-year-olds in seat belts only. The aim of this thesis is to develop mathematical frontal and side impact models and to use them to investigate and define the beneficial characteristics of restraint systems and other crash-related car parameters. It must be emphasized that children are better protected in rear-facing child restraints; they should remain rear-facing for as long as possible. Most children have outgrown the large rear-facing restraints by the age of about 4 years. This work concentrates on injury mitigation for those who have transited to forward-facing restraints.Models for two load cases were developed and validated. One of them was a frontal impact type, and the other was a near-side impact type. The frontal model was used both for a parameter study, to define beneficial restraint system characteristics for 3-year-olds, and for reconstructing three crashes in order to evaluate the head kinematics of the occupant model. The characteristics of the side impact load case were defined by analyzing real life crashes involving child occupants. The near-side impact model was used for a parameter study to define beneficial restraint system characteristics for 3- and 12-year-olds. It was also used to evaluate and propose improvements to the restraint systems within a range of common sitting positions for 12-year-olds.The validations carried out here showed that the models developed were suitable tools for conducting comparative studies of injury mitigation systems in both frontal and near-side impacts. The parameter studies showed that several of the restraint systems for adults also reduced the values measured by the child model. In the near-side impact, a curtain airbag, a thorax-pelvis airbag and a seat belt with a pretensioner reduced the head and chest injury measures of the two occupant models. To help mitigate injuries resulting from a frontal impact, the upper belt anchor point should be positioned so that the belt is routed near mid-shoulder (slightly toward the neck) and encloses the shoulder (tight fit). The lap belt anchor points should be positioned to make the lap belt angle as horizontal as possible without inducing submarining. Seat belts with pretensioners and load limiters also reduced the head injury measures for the 3-year-old occupant model.In side impacts, the results of the evaluation of common sitting positions suggested that extensive outboard, inboard and forward positions should be discouraged, while the restraint systems should be adapted to function with slight inboard, outboard and forward positions. This can be achieved with side supports integrated in the seat back, pre-impact (pre-brake) trigged seat belts, high performance full cell coverage curtain airbags, and/or thorax-pelvis airbags with an extended cover area. These findings are significant contributions to the continuous work of mitigating traffic accident induced injuries and fatalities to children.
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| 4. |
- Andersson, Marianne, 1969, et al.
(författare)
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Effect of booster seat design on children's choice of seating positions during naturalistic riding
- 2010
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Ingår i: Annals of Advances in Automotive Medicine - 54th Annual Scientific Conference; Las Vegas, USA, 17-20 October 2010. - 1943-2461. ; , s. 171-180
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Konferensbidrag (refereegranskat)abstract
- The purpose of this naturalistic study was to investigate the effect of booster seat design on the choice of children’s seating positions during naturalistic riding. Data was collected through observations of children during in-vehicle riding by means of a film camera. The children were positioned in high back boosters in the rear seat while a parent drove the car. The study included two different booster designs: one with large head and torso side supports, and one with small head side supports and no torso side supports. Six children between three and six years of age participated in the study. Each child was observed in both boosters. The duration of the seating positions that each child assumed was quantified. The design with large side head supports resulted more often in seating positions without head and shoulder contact with the booster’s back. There was shoulder-to-booster back contact during an average of 45% of riding time in the seat with the large head side supports compared to 75% in the seat with the small head supports. The children in the study were seated with the head in front of the front edge of the head side supports more than half the time, in both boosters. Laterally, the children were almost constantly positioned between the side supports of the booster in both seats. The observed seating positions probably reduce the desired protective effect by the side supports in side impact, and may increase the probability of head impact with the vehicle interior in frontal impact.
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| 5. |
- Andersson, Marianne, 1969, et al.
(författare)
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Evaluation of the Head Kinematics of the Q3 Model and a Modified Q3 Model by Means of Crash Reconstruction
- 2012
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 13:6, s. 600-611
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Tidskriftsartikel (refereegranskat)abstract
- Objective: One objective of this study is to evaluate the head kinematics of the Q3 model. Another objective is to evaluate the effect on head kinematics of increased thoracic spine flexibility; more humanlike mass distribution; and more humanlike body geometry in the Q3 model. The evaluations were based on the head kinematics of children deduced from real crashes and on new data of mass distribution and updated body dimensions for 3-year-olds. Methods: The head kinematics of the Q3 model was evaluated by comparing the Q3 model's head displacement response with the deduced response of 3-year-old children in real crashes. To do so, data from crashes were collected. The data were used to develop the mathematical vehicle and restraint system models (MADYMO, TASS, the Netherlands). Three crashes involving 3-year-old children in frontal impacts were reconstructed. The models were run 35 times each (one model per crash), each time with a different setting to each of the variables for which the exact value was not known. Examples of those variables include crash pulse, initial dummy position, and initial seat belt position. Two versions of the Q3 model were used: one that correlated with the Q3 ATD and one that was modified regarding anthropometry and thoracic flexibility. The basis for the updated anthropometry was new data regarding characteristic dimensions and mass distribution collected at a Swedish hospital. Results: In the anthropometry study, 26 children were measured. The main differences between the average of the measured children and the Q3 model were found in the mass distribution of the torso and thighs: the Q3's pelvis was too heavy and the thorax, abdomen/lumbar spine, and thighs were too light. Another difference was identified in the buttock-knee length. Two of the 3 reconstructed crashes had confirmed head impacts. The Q3 model responded with head kinematics that reflected the deduced courses of events for the real children in one of 3 crashes (the one without head impact). The modified Q3 model reflected the real children in 2 of 3 crashes. Conclusions: In high-severity, straight frontal crashes, the Q3 model predicted non-head impact adequately. However, in oblique frontal crashes, the Q3 model did not sufficiently predict the head impacts. The modified Q3 model predicted the head impacts better than the Q3 model did. Greater flexibility of the thorax and redistributed mass made a positive difference regarding the head kinematics.
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| 6. |
- Andersson, Marianne, 1969, et al.
(författare)
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Parameter study for child injury mitigation in near side impacts through FE simulations
- 2012
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 13:2, s. 182-192
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of this study is to investigate the effects by crash related car parameters on head and chest injury measures for 3- and 12-year-old children in near side impacts.Methods: The evaluation was made by using a model of a complete passenger car which was impacted laterally by a barrier. The car model was validated in two crash conditions: the IIHS and the USNCAP side impact tests. The SID-IIs and the HBM3 (THUMS 3-yo) finite element models were used for the parametric investigation (HBM3 on a booster). The car parameters were: vehicle mass, side impact structure stiffness, a head airbag, a thorax-pelvis airbag, and a seat belt with pretensioner. The studied dependent variables were: resultant head linear acceleration, resultant head rotational acceleration, chest viscous criterion, rib deflection, and relative velocity at head impact. The chest measurements were only considered for the SID-IIs.Results: The head airbag had the greatest effect on the head measurements for both of the occupant models. On average, it reduced the peak head linear acceleration by 54 g for the HBM3 and 78 g for the SID-IIs. The seat belt had the second greatest effect on the head measurements; the peak head linear accelerations were reduced on average by 39 g (HBM3) and 44 g (SID-IIs). The high stiffness side structure increased the SID-IIs head acceleration, while it had marginal effect on the HBM3. The vehicle mass had marginal effect on SID-IIs head accelerations, while the lower vehicle mass caused 18 g higher head acceleration for HBM3 and the greatest rotational acceleration. The thorax-pelvis airbag, the vehicle mass and the seat belt pretensioner affected the chest measurements the most. The presence of a thorax-pelvis airbag, high vehicle mass and a seat belt pretensioner all reduced the chest VC and peak rib deflection in the SID-IIs.Conclusions: The head and thorax-pelvis airbags have the potential to reduce injury measurements for both the SID-IIs and the HBM3, provided that the airbag properties are designed to consider these occupant sizes also. The seat belt pretensioner is also effective, provided that the lateral translation of the torso is managed by other features. The importance of lateral movement management is greater the smaller the occupant is. Light vehicles require interior restraint systems of higher performance than heavy vehicles do to achieve the same level of injury measures for a given side structure.
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| 7. |
- Andersson, Marianne, 1969, et al.
(författare)
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Rear Seat Child Safety in Near-Side Impacts: A Modeling Study of Common Sitting Positions
- 2013
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Ingår i: Traffic Injury Prevention. - : Informa UK Limited. - 1538-957X .- 1538-9588. ; 14:2, s. 198-208
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The purpose of this study was to evaluate and propose improvements to the injury mitigation systems, in near-side impacts, for 6 common sitting positions of young adolescents using a previously validated model. Methods: The evaluation was made by using a model of a complete passenger car, including head and thorax–pelvis air bags, which was impacted laterally by a barrier in 2 load cases. The SID-IIs finite element model was used for the evaluations and was seated in 6 different positions in the rear outboard seat: the nominal anthropomorphic test device (ATD) position, 1 inboard position, 3 outboard positions, and 1 braking (forward) position. These positions have previously been identified as common sitting positions in awake and asleep children. The studied dependent variables were head injury criterion (HIC) 36, resultant head linear acceleration, resultant head rotational acceleration, chest viscous criterion, and chest deflection. Results: The lowest head injury measures were seen in the braking positions and in the nominal ATD position, and the highest were seen in the inboard and outboard positions. The lowest chest injury measures were recorded in the inboard and nominal ATD positions, and the highest were recorded in the outboard and braking positions. The occupant in the outboard positions interfered with the air bags during their deployment. The occupant in inboard and braking positions tended to push the curtain air bag over the windowsill. Conclusions: Studies that investigate the injury mitigation effects in common sitting positions, beyond the nominal ATD position, are essential to highlight means to provide improved and robust safety for child occupants. This study was based on the SID-IIs 5th percentile female, which has very similar anthropometry to a 50th percentile 12-year-old. Therefore, the conclusions of this study are applicable to many 11-year-olds up to young adolescents, as well as to small females.The outboard and inboard positions of this study resulted in the highest head injury measures. Although all of the injury measures were only slightly higher than the nominal position, the trends suggest that, in near-side impacts, these positions should be discouraged. The extensively outboard positions resulted in unfavorable air bag positioning during deployment. The inboard position resulted in head strikes further forward of the nominal one; the curtain air bags need inflated cells at all locations of head strike.
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| 8. |
- Brolin, Karin, 1974, et al.
(författare)
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Safety of children in cars: A review of biomechanical aspects and human body models
- 2015
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Ingår i: IATSS Research. - : Elsevier BV. - 0386-1112. ; 38:2, s. 92-102
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Forskningsöversikt (refereegranskat)abstract
- The protection of children in motor vehicle crashes has improved since the introduction of child restraint systems. However, motor vehicle crashes remain one of the top leading causes of death for children. Today, computer-aided engineering is an essential part of vehicle development and it is anticipated that safety assessments will increasingly rely on simulations. Therefore, this study presents a review of important biomechanical aspects for the safety of children in cars, including child human body models, for scenarios ranging from on-road driving, emergency maneuvers, and pre-crash events to crash loading. The review is divided into four parts: Crash safety, On-road driving for forward facing children, Numerical whole body models, and Discussion and future outlook.The first two parts provide ample references and a state-of-the-art description of important biomechanical aspects for the safety of children in cars. That children are not small adults has been known for decades and has been considered during the development of current restraints that protect the child in the crash phase. The head, neck, thorax, and pelvis are body areas where development with age changes the biomechanics and the interaction with restraint systems. The rear facing child seat distributes the crash load over a large area of the body and has proved to be a very efficient means of reducing child injuries and fatalities. Children up to age 4. years need to be seated rearward facing for optimal protection, mainly because of the proportionally large head, neck anthropometry and cartilaginous pelvis. Children aged 4 up to 12. years should use a belt positioning booster together with the vehicle seat belt to ensure good protection, as the pelvis is not fully developed and because of the smaller size of these children compared to adults. On-road driving studies have illustrated that children frequently change seated posture and may choose slouched positions that are poor for lap belt interaction if seated directly on the rear seat. Emergency maneuvers with volunteers illustrate that pre-crash loading forces forward-facing children into involuntary postures with large head displacements, having potential influence on the risk of head impact. Children, similar to adults, benefit from the safety systems offered in the vehicle. By providing child adaptability of the vehicle, such as integrated booster cushions, the child-restraint interaction can be further optimized. An example of this is the significant reduction of lap belt misuse when using integrated boosters, due to the simplified and natural positioning of the lap belt in close contact with the pelvis. The research presented in this review illustrates that there is a need for enhanced tools, such as child human body models, to take into account the requirements of children of different ages and sizes in the development of countermeasures.To study how children interact with restraints during on-road driving and during pre- and in-crash events, numerical child models implementing age-specific anthropometric features will be essential. The review of human whole body models covers multi body models (age 1.5 to 15. years) and finite element models (ages 3, 6, and 10. years). All reviewed child models are developed for crash scenarios. The only finite element models to implement age dependent anthropometry details for the spine and pelvis were a 3. year-old model and an upcoming 10. year-old model. One ongoing project is implementing active muscles response in a 6. year-old multi body model to study pre-crash scenarios. These active models are suitable for the next important step in providing the automotive industry with adequate tools for development and assessment of future restraint systems in the full sequence of events from pre- to in-crash.
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| 9. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Skadereducerande Effekt av Uppvärmda Trottoarer, Gång- och Cykelstråk
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Nearly two out of three fall crashes with seriously injured pedestrians occur in the winter (December-March), i.e. twice as many pedestrians are seriously injured during these four months compared to the rest of the year. During the winter period (December-March) almost nine out of ten fall crashes are caused in the traffic environment due to slipping on ice/snow.
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| 10. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Skadereducerande Effekt av Uppvärmda Trottoarer, Gång- och Cykelstråk - En Inledande Studie
- 2019
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Nästan två av tre fallolyckor med allvarligt skadade fotgängare sker under vintern; dubbelt så många fotgängare skadas allvarligt under dessa fyra månader jämfört med årets övriga. Under vinterperioden orsakas nästan nio av tio fallolyckor i trafikmiljö av halka pga is/snö. De skador som drabbar fotgängare (och cyklister) på halt underlag behöver i allmänhet betydligt längre vårdtid jämfört med om det inte varit halt. Det finns alltså en stor skadereducerande potential i förbättrad halkbekämpning. Syftet med studien är att: - Kartlägga uppvärmda ytor i stadsmiljön för de största städerna i Sverige - Analysera den skadereducerande effekten av uppvärmda ytor för fotgängare, och (om möjligt) cyklister.
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