Tolerance analysis of mechanical components and assemblies is a key element in the industry for improving product quality reducing overall cost. This paper an attempt to propose methodology formulate compute kinematic assembly variations with respect critical dimensions (joint clearances) by calculating homogeneous matrix loops considering transforming rotation matrix, tolerance sensitivities, geometrical responses variations, sensitivity mechanism clearance joints different motion phases....

The primary problem in the finite element analysis of polyurethane jounce bumpers, bumper stops, or similar structures is identification a mathematical model for constitutive material. densities exterior area and interior usually differ owing to manufacturing process. This difference results inaccuracy when predicting mechanical behavior stop if homogeneous material used. Thus, this work proposes stratification method bumper. structure was divided into three regions (the ‘skin layer’,...

Two-dimensional materials have been developed as novel photovoltaic and photocatalytic devices because of their excellent properties. In this work, four δ-IV-VI monolayers, GeS, GeSe, SiS SiSe, are investigated semiconductors with desirable bandgaps using the first-principles method. These monolayers exhibit exceptional toughness; in particular, yield strength GeSe monolayer has no obvious deterioration at 30% strain. Interestingly, also possesses ultrahigh electron mobility along x...

Hydrogen is an ideal alternative fuel for internal combustion engines due to its fast rate and near-zero carbon emissions. To further investigate the impact of injection strategy on performance under various excess air coefficients loads, experimental methods were employed systematically study timing, pressure, dual injection. The results demonstrate that appropriately delaying hydrogen timing can improve thermal efficiency by up 2.6% reduce NOx emissions equivalent nearly 88%. While...

In this study, a mixed meta-modeling-based optimization method has been proposed and applied to commercial vehicle for crashworthiness design subjected the frontal crash. A full-scale finite element model of built validated by crash test. The front frame parts have separated build sub-model optimization. Sensitivity analysis performed find factors contributing most performance using experiments. With reduced dimensions space, meta-models criteria (i.e. specific energy absorption, peak crush...

Four-bar linkages are critical fundamental elements of many mechanical systems, and their design synthesis is often mathematically complicated with iterative numerical solutions. Analytical methods based on Fourier coefficients can circumvent these difficulties but have issues time parameters assignment for path generation without prescribed in previous studies. In this paper, an improved Fourier-based point-to-point combination method presented, which generates more points by approximation...

In this paper, fatigue damage analysis and structural improvement of a commercial vehicle cab were carried out, in which simulation technique durability road tests combined. A full-scale finite element model the was established then validated by means physical testing its stiffness modal performance. The loading spectra, accordance with test, obtained adopting virtual iteration method. With model, stress distributions under unit excitation determined. used to assess total life employing...

Fault diagnosis of gearboxes based on vibration signal processing is challenging, as signals collected by acceleration sensors are typically a nonlinear mixture unknown signals. Furthermore, the number source usually larger than that because practical limitation sensor positions. Hence, fault characterization actually underdetermined blind separation (NUBSS) problem. In this paper, novel NUBSS algorithm kernel independent component analysis (KICA) and antlion optimization (ALO) proposed to...

In this paper, a multi-rate signal processing technique is proposed for obtaining higher-order derivatives of digital signals with an improved signal-to-quantization noise ratio (SQNR). The consists classical oversampling analog-to-digital conversion (ADC) unit dithering process and multi-stage down sampling followed by high performance differentiator cascaded using decimator factor two. the processing, each stage contains simple half-band low-pass filter decimation uses extremely small FIR...

This study conducted extensive experimental research on key working process parameters and pre-chamber geometric parameters, using a 0.5L single-cylinder engine capable of freely switching structures. The results revealed that when the excess air coefficient (lambda) exceeded 1.7, increasing mixture's dilution ratio reduced cylinder temperature, while raising compression (CR) further suppressed detonation. As CR increased from 12.48 to 16.4, indicated thermal efficiency (ITE) demonstrated an...

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Abstract Four-bar linkages are critical fundamental elements of many mechanical systems, and their design synthesis is often mathematically complicated with iterative numerical solutions. Analytical methods based on Fourier coefficients can circumvent these difficulties but have sampling points adjustment solutions the equations in previous studies. In this paper, an improved Fourier-based analytical method presented, which transforms function generation planar four-bar into a problem...

To investigate the crashworthiness capacity of a M1 type commercial vehicle, full-scale finite element (FE) model vehicle has been established. On basis FE model, impact simulation subject to 100% frontal carried out, and results have verified with physical test. The analysis deformation path energy absorption indicates that lacks sufficient area its peak crash acceleration (PCA) is too high, which raises huge challenge for sequent development safety restraint system. enhance some structural...

Abstract The flow field of the air duct in a shelter was studied using computational fluid dynamics (CFD) and experiment methods. improvement methods vortexes at bends were analysed. It found that corner chamfer installation guide plates have significant effect on improving vortex. optimized scheme expanded inlet outlet area chamfered inner bends, then uniformity velocity outlets both sides straight increased by 47% 42% respectively. placed for simulation. results showed total volume has...