ACCEL2

Bulk Data Entry Defines static acceleration loads at a specific SET of GRID points in the model. Additionally, scale factors for varying direction acceleration loads can be defined using tabular data.

Attention: Valid for Implicit and Explicit Analysis

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
ACCEL2 SID SSID CID A N1 N2 N3    
  DIR TID              

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
ACCEL2 100 4 0 2.0 1.0 3.0 5.0    
  X 11              

Definition

Field Contents SI Unit Example
SID Acceleration load set identification number.

(Integer > 0)

  
SSID Identification for a SET of Grid points at which the acceleration load is applied.
Integer
Specifies an identification number for the set.
<String>
Specifies a user-defined string label for the set. 5

(Integer > 0 or <String>)

  
CID Coordinate system identification number.
= 0 (Default)
References the basic coordinate system

(Integer ≥ 0, or blank)

  
A Scale factor for the acceleration load vector.

Default = blank (Real, if non-zero loading is required, then A should be non-zero)

  
N1,N2,N3 Acceleration load vector components in the coordinate system CID.

Default = blank (Real, if non-zero loading is required, then a minimum of one Ni should be non-zero)

  
DIR Component direction of the acceleration load variation.

Default = blank (Character; one of X, Y, or Z)

  
TID Identification number of a TABLED1 entry that specifies the Location (LOCi) versus Scale Factor (VALi) values (similar to the ACCEL entry).

Default = blank (Integer > 0)

  

Comments

  1. The acceleration load applied to all grid points in the referenced SSID SET in the model is given by:(1)
    a = V A L C * V A L V * N MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaebbnrfifHhDYfgasaacH8srps0l bbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0R Yxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGa caGaaeqabaqaaeaadaaakeaacaWHHbGaeyypa0JaamOvaiaadgeaca WGmbWaaSbaaSqaaiaadoeaaeqaaOGaaiOkaiaadAfacaWGbbGaamit amaaBaaaleaacaWGwbaabeaakiaacQcacaWHobaaaa@3CD1@
    Where,
    a
    Acceleration load.
    N
    Vector with components N1, N2, and N3.
    V A L MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGwbGaamyqaiaadYeaaaa@3B49@
    Directional varying scale factor which is defined based on DIR and TID fields. This is not mandatory and if DIR and TID are both blank.
    V A L C MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaebbnrfifHhDYfgasaacH8srps0l bbf9q8WrFfeuY=Hhbbf9v8qqaqFr0xc9pk0xbba9q8WqFfea0=yr0R Yxir=Jbba9q8aq0=yq=He9q8qqQ8frFve9Fve9Ff0dmeaabaqaciGa caGaaeqabaqaaeaadaaakeaacaWGwbGaamyqaiaadYeadaWgaaWcba Gaam4qaaqabaaaaa@3521@
    Is applied and a constant acceleration load is applied for the whole model.
    The scale factor VAL for each grid in the specified SET SSID in the model is automatically determined by linear interpolation between VALi for the DIR component of the corresponding LOCi between which the required grid point lies. If the GRID point's DIR coordinate in the coordinate system CID is outside the range specified by LOCi, the corresponding VAL is determined either from VAL1 or VALn (Figure 1). A minimum of two pairs of (LOCi and VALi) should be specified.


    Figure 1. Acceleration Load Factor (VAL) versus Location along DIR (LOC)
  2. The acceleration loads specified in the ACCEL2 entry can be combined with other loads, such as FORCE, MOMENT, GRAV, ACCEL, and ACCEL1, through the LOAD Subcase Information Entry. The SID on the ACCEL entry should be unique with regard to any other load entry.
  3. The acceleration load does not include effects, due to mass on SPOINTs.
  4. The ACCEL2 entry is similar to the ACCEL entry. The ACCEL load is applied to the entire model while the ACCEL2 load is calculated similar to ACCEL but applied only to the specified SET of grid points (SSID). Additionally, an extra scale factor A is applied to the acceleration load vector.
  5. String based labels allow for easier visual identification of sets, including when being referenced by other cards. For more details, refer to String Label Based Input File in the Bulk Data Input File.
  6. This card is represented as a force load in HyperMesh.