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Typical error message found in the LUSAS Solver text output file (*.OUT):

***DATABASE ERROR*** Illegal value of i,j,k or l used to dimension an array


The reason for this message is that the problem size is too large. Because of 32bit data handling, the following must be true:

(Max Frontwidth +3)*Number of Freedoms < 2.147484E+09 (i.e. 2^31)

The key parameters are, then, the maximum frontwidth and the number of freedoms in the problem. These may be obtained from the LUSAS output file for a particular analysis.

Frontwidths are typically in the range 100-6000. Large frontwidths can be a result of:

a) the extensive use of slidelines or constraint equations over discrete components. Larger frontwidths are to be expected with this, although we do optimise as much as possible.

b) cracks in the mesh

To overcome this limit:

a) Check for mistakes in the assignment of the slidelines that can potentially stretch nodal connectivity in such a way as to significantly affect the frontwidth.

b) Try other frontwidth optimisers on the problem. 

c) Reduce the number of elements and/or, if using higher order elements, change to lower order

d) Use tied slidelines or constraint equations to abruptly change the mesh refinement away from the area of interest and, hence, decrease the number of elements

e) Use symmetry conditions where possible


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