ACCEL

Bulk Data Entry Defines acceleration loads to all grids in the model. These loads can either be constant or vary in a particular direction over sections of the model.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
ACCEL SID CID N1 N2 N3 DIR      
  LOC1 VAL1 LOC2 VAL2 etc.        

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
ACCEL 12 0 1.0 2.0 .10 Y      
  0.0 4.0 200.0 5.0          

Definitions

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

(Integer > 0)

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

(Integer ≥ 0, or blank)

  
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)

  
LOCi Location of the scale factor to the applied acceleration load along direction DIR in the coordinate system CID.

Default = blank (Real)

  
VALi Load scale factor at the location LOCi.

Default = blank (Real)

  

Comments

  1. The acceleration load applied to all grid points in the model is given by:(1)
    a = VAL * N
    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 scale factor.

    It is not mandatory to define the directional scale factor. No scale factor is defined if you do not define DIR, VALi, and LOCi. In such cases, only N1, N2, and N3 can be defined to apply a constant acceleration load throughout the model.

    If DIR, VALi, and LOCi are defined, then the scale factor VAL for each grid in the model is automatically 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, if such directional scaling is required.


    Figure 1. Acceleration Load Factor (VAL) versus Location Along DIR (LOC)
  2. The acceleration loads specified in the ACCEL entry can be combined with other loads, such as FORCE, MOMENT, GRAV, ACCEL1, and ACCEL2, 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. This card is represented as a force load in HyperMesh.