Failure Analysis and Optimization of the Tie Rod Using FEA

A car’s steering wheel is used to connect the steering gear which is connect to the wheels via the tie rod ends. The main use of the tie rod end is to ensure the wheels are aligned. Hence the functioning of tie rod is crucial for steering as well as suspension performance of vehicle. Today’s world is competitive with respective to efficiency as well as economical in price, every organization striving for cost effective product at a lower price and within minimum period for ‘time to market. In this work, an attempt is made on optimization of the tier rod through changing materials and to reducing the weight. FEA analysis is performed on solid section and hollow sections with different thicknesses. The stress results at critical locations for different design iterations are discussed in this work. From the FEA results it is observed that the effected wright for hollow section is reduced by 18.15 % compare to solid section. Keywords: Tie rod, ANSYS, CATIA, Stress, optimization

Effect of rescanning with reduced interlayer times on microstructure and properties of titanium alloy via selective laser melting

In the process of selective laser melting, laser rescanning technology is often used to optimize the residual stress and other properties of the formed parts. In order to improve the performance of parts and reduce the manufacturing time concurrently, this paper proposed a combined rescanning strategy. Based on finite element analysis, molten pool solidification behavior was simulated and studied. Ti6Al4V alloy samples were fabricated and analyzed by changing the rescanning strategies and process parameters. The microstructure, relative density, size of pore defects and residual stress were investigated under different rescanning strategies. It can be seen that the average cooling rate ranked in a descending order of SLM > re-SLM+IL1 > re-SLM, and samples formed by rescanning without layer interval had the best relative density and residual stress optimization effect, while the microstructure of each scanning strategy was all acicular α′ phase. When the number of rescanning interlayers and laser power was “one-layer” and 140 W respectively, the residual stress went down from 353 to 294 MPa. Finally, a simplified model was proposed to calculate the time cost for fabrication of rescanning with reduced interlayer times.

Radial Turbine Thermo-Mechanical Stress Optimization by Multidisciplinary Discrete Adjoint Method

This paper addresses the problem of the design optimization of turbomachinery components under thermo-mechanical constraints, with focus on a radial turbine impeller for turbocharger applications. Typically, turbine components operate at high temperatures and are exposed to important thermal gradients, leading to thermal stresses. Dealing with such structural requirements necessitates the optimization algorithms to operate a coupling between fluid and structural solvers that is computationally intensive. To reduce the cost during the optimization, a novel multiphysics gradient-based approach is developed in this work, integrating a Conjugate Heat Transfer procedure by means of a partitioned coupling technique. The discrete adjoint framework allows for the efficient computation of the gradients of the thermo-mechanical constraint with respect to a large number of design variables. The contribution of the thermal strains to the sensitivities of the cost function extends the multidisciplinary outlook of the optimization and the accuracy of its predictions, with the aim of reducing the empirical safety factors applied to the design process. Finally, a turbine impeller is analyzed in a demanding operative condition and the gradient information results in a perturbation of the grid coordinates, reducing the stresses at the rotor back-plate, as a demonstration of the suitability of the presented method.

Finite Element Analysis Model and Residual Stress Optimization in Rotor Welding Process

In this paper, the finite element method (FEM) is conducted for thermal and mechanical analysis of a half 2D axisymmetric welded rotor model. The temperature results after welding are obtained and supported by the experiment results. Furthermore, the thermal strain and residual stress of the weld are analyzed in detail by considering solid-state phase transformation (SSPT). Besides, parametric optimization method is adopted to optimize the region of large stress distribution. By choosing the weld pass number as the optimized parameter, the area decreases by 5.4% when the optimal pass number is 18. The axial and hoop stress distributions are obtained at the inner and outer surfaces near the weld for the better stress distribution.