**Model** | Model | Model to be optimized | Model |

**Elem Ids** | ElemIds | List of identifiers of shells that take part in cross section design. By default all are included. | String |

**LCases** | LCases | List of load cases that are considered for BESO | Integer |

**Target mass ratio** | TargetRatio | Target Ratio of remaining mass to initial mass of all elements that take part in the BESO (also inactive elements count). | Number |

**MaxIter** | MaxIter | Maximum number of iterations | Integer |

**ER** | ER | Evolutionary volume ratio: V(k+1) = V(k)*(1+-ER). If ER;0 (the default) then ER is set to (1-TargetRatio)/MaxIter+ARmax/2. | Number |

**ARmax** | ARmax | Ratio between maximum number of elements to be added per step and all elements. | Number |

**Nhist** | Nhist | Number of iterations between the steps which are used for calculating the convergence criteria. | Integer |

**Conv** | Conv | Relative change of the mass between two iterations Nhist cycles apart below which convergence is assumed. | Number |

**Rmin** | Rmin | Radius of influence [m] for determining the element sensitivity. If Rmin;0 (the default) then Rmin is set to the characteristic element length which is calculated as (total Area/number of elements)^(0.5)*2. | Number |

**Rexp** | Rexp | Exponent for weighting the distance from nodes to element centers for the calculation of sensitivities. | Number |

**KillThick** | KillThick | Shell thickness used for soft kill of shell elements. | Number |