Laserfiche WebLink
FIELD SCIENCE <br /> GMax= 111, HIC = 320 and SI= 358 <br /> 124 <br /> 100 <br /> e0 <br /> eo <br /> CD ■A_ <br /> 40 <br /> 20 <br /> e m o < v m o <br /> 0 0 0 0 0 0 _ _ n r r <br /> Time (mS) <br /> Figure 2.Gmax,Head Injury Criteria and Severity Index values for a 100%crumb rubber Will synthetic football field <br /> with no shock pad below the carpet.Time is In milliseconds. <br /> However, softer is only good to a certain extent. Too soft a surface �� M - <br /> slows play and causes muscle fatigue. If the strike base (crushed is very THE NAME MUST CO ON■ <br /> ® compressible then the player may actually strike the base (crushed <br /> stone.asphalt or concrete)during the impact. <br /> The hardness of natural turf playing systems is also dependent on An Airfield is the ultimate sports turf <br /> many things that most turf managers are familiar with.Turf variables ,. drainage system whether you are <br /> playing on natural or artificial turf. <br /> include the age and type of turf,turf density,amount of groundcover, .� <br /> the mowing height and the presence of some thatch. Soil factors J Art/kW Tro/aerean: <br /> 31„ .-/ Draw w <br /> s rmrtltly taster <br /> include texture,moisture content,degree of compaction and whether i/- Recluses mullet=mrc <br /> or not the soil is frozen. Synthetic turf manufacturers,based on mar- 4 Reduces GMax <br /> !amasses cutter mugraaon <br /> keting literature, want their fields to play like a pristine natural turf Emrwis Marxtvlg water <br /> playing surface. strong enough Mr vehWs <br /> Below entse praying Surface <br /> Ax wain lot heating aro cooling <br /> Assessing hardness: Gmax,HIC and SI Mows gushing am sancairy <br /> Impact severity has been studied for many years by automotive and Maintains level Massy curfew <br /> consumer product safety researchers. Of most concern is the possi- Natter Tel Benefits: <br /> bility of a life threatening head and neck injury. These injuries have claws rsmarkaoytamer <br /> Redoes"vlstalmtm time <br /> been related to how quickly a human head decelerates during an Reduces irrigation requirements <br /> impact and the duration of that deceleration. Deceleration character- <br /> istics of an impact tell us a lot about the hardness of the playing sur- . <br /> Reduces tm swnarlw cats <br /> face. A harder surface results in an impact that has a very short but Be p1arc a mr m taaaw la <br /> very fast deceleration. -Greeter rootmass <br /> Deceleration (ft./sec./sec.) is the rate at which velocity (ft./sec.) -Gas c'°ta t°eough eml <br /> decreases. It is the opposite of acceleration(the rate at which velocity p I <br /> is increasing).Deceleration can also be expressed as the ratio of decel- <br /> eration to acceleration due to gravity,g. This ratio is called G.At some a airfield <br /> point over the course of an impact there is a maximum rate of deceler- <br /> ation.This translates into a maximum ratio of deceleration to accelera- s y s t e m s. <br /> Lion,Gmax. Gmax is also called peak deceleration and is the value we 405.359.3775 <br /> aidieldsystems.com <br /> are most interested in when assessing the hardness of a playing field. <br /> WI in 114 on reader service form or visit http://mershotnns.cem19133-114 <br /> www.sportsturfmanager.org SportsTurf 11 <br />