Oka Wear Model

The Oka or Impact Wear contact model extends any Base Model to give an estimation of erosion depth for Geometry surfaces due to particle impacts.

This model originates from the work by Oka and Yoshida (Oka and Yoshida, 2005). Erosive wear occurs when particles impact equipment surfaces. This type of wear can be modeled using the widely adopted Oka wear model (Oka and Yoshida, 2004), which predicts the volume of removed material due to particle impact as a function of the particle size, impact velocity, and impact angle. This model takes only two inputs - the Vickers hardness of the worn material and an empirical wear constant. The results are provided in terms of wear depth on Geometry mesh elements similar to the Archard Wear model.

The wear depth is determined as follows: 

D ω = g ( α ) E ( α ) m p A MathType@MTEF@5@5@+= feaahyart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiramaaBa aaleGabaGkgiabeM8a3bqabaGccqGH9aqpdaWcaaqaaiaadEgacaGG OaGaeqySdeMaaiykaiaadweacaGGOaGaeqySdeMaaiykaiaad2gada WgaaWcbaGaamiCaaqabaaakeaacaWGbbaaaaaa@4493@

Where dw is the wear depth, α is the particle impact angle, g(α) is the impact angle dependence of normalized erosion, E(α) is the wear volume per unit mass, mp is the mass of the particle and A is the Geometry element area. 



 

The wear volume per unit mass is defined as:

E ( α ) = 65 W − k 1 υ 104 2.3 H υ 0.038 D 0.326 0.19 MathType@MTEF@5@5@+= feaahGart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyramaaBa aaleaacaGGOaGaeqySdeMaaiykaaqabaGccqGH9aqpcaaI2aGaaGyn aiaadEfacqGHsisldaahaaWcbeqaaiaadUgadaWgaaadbaGaaGymaa qabaaaaOWaaeWaaeaadaWcaaqaaiabew8a1bqaaiaaigdacaaIWaGa aGinaaaaaiaawIcacaGLPaaadaahaaWcbeqaaiaaikdacaGGUaGaaG 4maiaadIeadaWgaaadbaGaeqyXduhabeaalmaaCaaameqabaGaaGim aiaac6cacaaIWaGaaG4maiaaiIdaaaaaaOWaaeWaaeaadaWcaaqaai aadseaaeaacaaIWaGaaiOlaiaaiodacaaIYaGaaGOnaaaaaiaawIca caGLPaaadaahaaWcbeqaaiaaicdacaGGUaGaaGymaiaaiMdaaaaaaa@57FE@

Where W is the materials wear constant, v is the particles impact velocity, Hv is the Vickers hardness of worn material, D is the particle diameter and k1 is an experimentally derived coefficient. 



The impact angle dependence of normalized erosion is defined as: 

g α = sin α 0.71 H υ 0.14 1 + H υ 1 − sin α 2.4 H υ − 0.94 MathType@MTEF@5@5@+= feaahyart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4zamaabm aabaGaeqySdegacaGLOaGaayzkaaGaeyypa0Jaci4CaiaacMgacaGG UbWaaeWaaeaacqaHXoqyaiaawIcacaGLPaaadaahaaWcbeqaaiaaic dacaGGUaGaaG4naiaaigdacaWGibWaaSbaaWqaaiabew8a1bqabaWc daahaaadbeqaaiaaicdacaGGUaGaaGymaiaaisdaaaaaaOWaaeWaae aacaaIXaGaey4kaSIaamisamaaBaaaleaacqaHfpqDaeqaaOWaaeWa aeaacaaIXaGaeyOeI0Iaci4CaiaacMgacaGGUbWaaeWaaeaacqaHXo qyaiaawIcacaGLPaaaaiaawIcacaGLPaaaaiaawIcacaGLPaaadaah aaWcbeqaaiaaikdacaGGUaGaaGinaiaadIeadaWgaaadbaGaeqyXdu habeaalmaaCaaameqabaGaeyOeI0IaaGimaiaac6cacaaI5aGaaGin aaaaaaaaaa@625B@

Where sin α 0.71 H υ 0.14 MathType@MTEF@5@5@+= feaahyart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaci4CaiaacM gacaGGUbWaaeWaaeaacqaHXoqyaiaawIcacaGLPaaadaahaaWcbeqa aiaaicdacaGGUaGaaG4naiaaigdacaWGibWaaSbaaWqaaiabew8a1b qabaWcdaahaaadbeqaaiaaicdacaGGUaGaaGymaiaaisdaaaaaaaaa @44E9@ captures the normalized erosion due to repeated deformation and 1 + H υ 1 − sin α 2.4 H υ − 0.94 MathType@MTEF@5@5@+= feaahyart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca aIXaGaey4kaSIaamisamaaBaaaleaacqaHfpqDaeqaaOWaaeWaaeaa caaIXaGaeyOeI0Iaci4CaiaacMgacaGGUbWaaeWaaeaacqaHXoqyai aawIcacaGLPaaaaiaawIcacaGLPaaaaiaawIcacaGLPaaadaahaaWc beqaaiaaikdacaGGUaGaaGinaiaadIeadaWgaaadbaGaeqyXduhabe aalmaaCaaameqabaGaeyOeI0IaaGimaiaac6cacaaI5aGaaGinaaaa aaaaaa@4E43@ captures the cutting behavior of the impact. Using this model in EDEM requires the additional input of the material’s Vickers hardness, Hv(GPa), the material’s Wear Constant, WOka.
Interaction Configurable Parameters Position
Particle to Geometry Assign a wear constant, the Vickers Hardness value for each Equipment Material-Particle interaction and Scaling Factor (if Deformation enabled). Last
EDEM also provides the option to deform the Geometry according to the quantitative results given by the Impact Wear model.


In the Oka Wear Model Parameter values dialog box:
  1. Select the Enable Deformationcheck box to enable Geometry deformation.
  2. If you select Enable Deformation, you must specify the Scaling Factor which allows the deformation results to be scaled as desired.
Material WOka Vickers Hardness (GPa)
Carbon Steel 3 0.54 - 1.18
Stainless Steel 10 1.770
Aluminum 1000 0.36