anisotropic plasticity and failure prediction in wood ... - ANSYS Users

More documents

Recommendations

Info

ANISOTROPIC PLASTICITY AND FAILURE PREDICTION IN WOOD COMPOSI... The unbolted end of the member was restricted from displacements in the Y-direction by applying a zerodisplacement boundary along the plane normal to the Y-direction as shown in Figure 9. The two planes of symmetry in the wood and dowel were modeled with zero-displacement boundary conditions in the planes normal to the X- and Z-directions. Displacements were applied to the end of the bolt to simulate the experimental displacement-controlled conditions. These displacements were fixed in the Y-direction towards the bolted end of wood member. One model was used for each connection geometry and set of material properties. The solution was non-linear due to material non-linearity and the iterations required to enforce the contact compatibility. Displacements to the end of the dowel were imposed in small steps to assist in convergence. Data was saved for each step. Convergence was not typically possible beyond total displacement of roughly 2.5 mm (0.1 inch) even though experimental displacements were much larger. Enough information about the performance of the connection could be determined, however, as will be shown shortly. CASE II - Results Load-displacement curves from the experiments and from ANSYS are shown in Figure 10 for loading parallel-to and perpendicular-to-grain, respectively. Specimens with 9.5 mm (3/8 inch) and 19 mm (3/4 inch) diameter, d, bolts are discussed here. Two end distances, 2d and 4d were chosen to force a change in the mode of failure. Values of maximum load, maximum displacement along with the mode failure are listed in Tables 7, 8 and 9, each corresponding to the direction of loading. Figure 10. LOAD-DISPLACEMENT CURVES FOR SINGLE-BOLT CONNECTIONS LOADED (A) PARALLEL-TO-GRAIN, AND (B) PERPENDICULAR-TO-GRAIN. DARK LINE IS RESULT FROM ANSYS file://C:\Documents%20and%20Settings\beh\Local%20Settings\Temp\~hhC936.htm Page 18 of 22 7/9/2002
ANISOTROPIC PLASTICITY AND FAILURE PREDICTION IN WOOD COMPOSI... In general, load-displacement curves were well matched. Linear and non-linear load-displacement behavior were predicted corresponding to the experimental results. Ultimate strengths, listed in Tables 7 to 9, were always predicted conservatively to be within 50 to 84% of the experimental averages for all loading directions. Ultimate displacements were found to be within 17 to 88% of the experimental averages, however, displacement data along with the load-displacement curves provide information about the overall expected behavior of a particular connection. Mode of failure predictions were well matched with experimental observations. Table 7. Failure data for single-bolt connections loaded parallel-to-grain Bolt size End dist. Max. load (lbs.) Experiments (a) Model (b) Model/experiments Max. disp. (in.) Failure mode Max. load (lbs.) Max. disp. (in.) Failure mode file://C:\Documents%20and%20Settings\beh\Local%20Settings\Temp\~hhC936.htm Load Disp. Page 19 of 22 7/9/2002
Page 1 and 2: ANISOTROPIC PLASTICITY AND FAILURE
Page 17: ANISOTROPIC PLASTICITY AND FAILURE

anisotropic plasticity and failure prediction in wood ... - ANSYS Users

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?