This paper presents a design optimization method for continuum compliant structures. The developed optimization tool enables automated design, analysis and optimization of the compliant structures in a single simulation environment. The associated algorithm used automatically analyses the stress distribution occurring under certain loading and deformation conditions of initial designs defined by the user, adjusts a uniform stress distribution among individual flexure hinges by automated dimensioning and finalizes the design by integrating mechanical stops automatically matched with the kinematic capacity of individual hinges. In order to prove the advantages of the proposed optimization method, validation tests were performed under static and dynamic loading conditions. Results of the experiments showed that, compared to the non-optimized ones, optimized structures with the developed tool exhibit more uniform curvatures which indicate more even stress distribution among the individual hinges; up to 25% value increase in terms of maximum bearable load and maximum permissible deflection angle; less plastic deformation in case of overloading and up to 100% increased fatigue life.

In this work, we investigated the effect of geometric parameters on the payload capacity of Ti-6Al-4V flexure hinges taking plastic deformation as a boundary failure criterion into account. Finite element and experimental analysis were performed in combination to increase the significance of the findings. For both simulations and experiments rectangular cross section flexure hinges were designed with varying thickness, length and width. While varying one of the parameters, the others were kept constant in order to see the individual influence of that particular parameter. The samples were fabricated using laser cutting of Ti-6Al-4V (Grade 5) metal sheets to ensure optimum dimensional accuracy. In the experimental procedure, the samples were fixed at the proximal end and exposed to gradually increasing vertical loads at the distal end by using weights. Simultaneously, they were exposed to a counteracting moment by pull-wire actuation attached on the tip to simulate the realistic actuation-loading behavior. For the sake of a uniform comparison of the samples with different dimensions, a state of equilibrium was defined such that the proximal and distal ends of the hinge were parallel. As soon as this state was achieved, the poses in each loading state were documented by a digital microscope for later postprocessing. On the other hand, the simulations were constructed in a way that permitted the experimental approach to be reflected in the simulation environment as realistically as possible. While performing a deformation-based simulation, the surface on which the payload was acting was blocked against rotation around the lateral axis so that the state of equilibrium could be maintained. The hinges were deflected with gradually increasing deformation in the vertical axis until 0.2% plastic strain occurred in the unloaded state. At this point the deformations in the vertical axis for both loaded and unloaded states were recorded to be compared with the experimental values. The forces leading to the deformation in the loaded state were calculated as output of the simulation and recorded as payload capacity. Consequently, the deformations obtained by analyzing the images captured during the experiments were compared and matched with the ones obtained from the simulations. The experimental loads leading to these deformations were recorded as experimental payload values. In the first step towards the evaluation of the results, payload values obtained from experiments and simulations were compared to check the consistency of the process. Subsequent to verifying the consistency, the effect of the geometric parameters on the payload progression was analyzed based on the simulation results. Nonlinear multidimensional regression was performed to come up with a design guideline which approximates the payload capacity based on the dimensional parameters. The proposed guideline estimates the payload value as proportional to width, inversely proportional to length and proportional to the 1.6th power of thickness.

Powder Bed Fusion of Metals using a Laser Beam (PBF-LB/M) is increasingly utilized for the fabrication of complex parts in various industrial sectors. Enabling a robust and reproducible manufacturing process is one of the main goals in view of the future success of PBF-LB/M. To meet these challenges, alloys that are specifically adapted to the process are required. This paper demonstrates the successful interplay of simulation studies with experimental data to analyze the basic phenomena of in situ alloying. The meshless Smoothed-Particle Hydrodynamics (SPH) method was employed for the numerical simulation of two-component powder systems considering both thermodynamics and fluid mechanics in the solid and the melt phase. The simulation results for the in situ alloying of stainless steel 316L blended with the aluminum alloy AlSi10Mg were enriched and validated with the data from a novel experimental test bench. The combination of both approaches can enhance the understanding of the process for in situ alloying. Therefore, future investigations of the PBF-LB/M process with multi-component powder systems can benefit from detailed numerical studies using SPH.