Numerical study of multiplanar tubular DX-joints subject to axial loads

In this paper, 20 multiplanar DX-joints (double X) with in-plane braces and out-of-plane braces subjected to various combination of axial loads were a nalysed. The multiplanar effect of loaded and unloaded out-of-plane braces and the load-interaction of multiplanar DX-joints were investigated. The in fluence of geometric parameters on the stress concentration factors of the joints was also studied. The results obtained from the analyses of multipla nar DX-joints are compared with those of the corresponding uniplanar X-join ts. It is found that, when the out-of-plane braces are not loaded, the mult iplanar effect is not significant when the brace diameter is much smaller t han the chord diameter. When the out-of-plane braces are loaded, the hot sp ot stresses are found to be lower or higher than the values predicted based on uniplanar joints. The deviation can be as much as 87% or 94%, respectiv ely, depending on the combination of the load conditions and geometrical pa rameters. (C) 1999 Elsevier Science Ltd. All rights reserved.