Tolerance allocation optimization (TAO) is a crucial step in the manufacturing process of portal milling machine (PMM). Traditional design approaches often consider only machining errors arising from geometric errors. However, thermal characteristics bi-rotary head (BRMH), which significantly tool accuracy, are frequently overlooked. Hence, novel TAO model PMM proposed, considering BRMH across multiple operating conditions. Firstly, based on multi-body system (MBS) theory and homogeneous...

In view of the safety construction long foundation pit new upper span to existing subway under urban complex environment conditions, combined with intersection section first line across north–south Expressway in Shenyang, mechanical properties during were studied by means numerical simulation and on-site monitoring. The results showed that general deformation characteristic metro tunnel was “uplift first, then restrain”. local an unloading rebound cross region, a compression occurs outside...

With the increase in working time, geometric errors of a Horizontal Machining Center (HMC) will also under load, temperature, and wear conditions, decreasing machining accuracy. As HMC is high-accuracy machine tool with high nonlinear system, there complex coupling relationship between errors. Therefore, how to thoroughly evaluate ability maintain its accuracy extension time an important way for control quality. In this paper, defined as reliability, that is, specified can work normally...

Two new triterpenoid glucosides, Heritiera A (1) and B (2), six known analogs (3-8) were isolated from littoralis Dryand. Their structures identified by comprehensive spectroscopic analyses comparisons with the literature. The anti-inflammatory activity of isolates H. was evaluated using a lipopolysaccharide (LPS) stimulated RAW 264.7 cells model. result showed that four triterpenoids exhibited potent activity. Among these compounds, compound 2 substantially inhibits release nitric oxide...

Landslide susceptibility mapping (LSM) predicts potential landslide risks based on historical landslides, playing a crucial role in prevention and control. This study proposes novel approach for LSM open-pit mines, leveraging comprehensive case database. method addresses the limitations of traditional approaches, such as sensitivity to records, low-quality inventories, limited dataset size. By expanding training set incorporating case-based reasoning (CB-LSM) using Long Short-Term Memory...

The bolted joint is widely used in heavy-duty CNC machine tools, which has huge influence on working precision and overall stiffness of machine. process parameters group bolt assembly directly affect the connected parts. dynamic model joints established based fractal theory, surface calculated. In order to improve total assembly, an improved particle swarm optimization algorithm with combination time-varying weights contraction factor proposed. input are preloading bolts, dimension,...

Small-modulus gears, which are essential for motion transmission in precision instruments, present a measurement challenge due to their minuscule gear gaps. A high-precision method under the influence of positioning errors is proposed, enabling precise evaluation machining quality small-modulus gears. Firstly, compound platform gears developed. Using 3D model system, mathematical relationships governing between various components analyzed. Secondly, formation mechanism error revealed and its...

Based on Ježek method of computing the elastic-plastic buckling member under axial compressive load and bending moment, analytical expressions calculating ultimate about neutral axis with moment inertia for a square steel tube column are derived. By degenerated into rectangular compared values finite element analysis (FEA) method, it shows that in this paper is valid, which provides new theoretical study member.

Based on Ježek method of computing the elastic-plastic buckling member under axial compressive load and bending moment, analytical expressions calculating ultimate about neutral axis with maximum moment inertia for an H-shaped column are derived. By degenerated into rectangular compared values finite element analysis (FEA) method, it shows that in this paper is valid, which provides a new theoretical study member.

Landslides seriously threaten the safety of human life and property. In order to predict on-set potential landslides, this paper first characterizes physical mechanical parameters rock mass on basis core quality designation identification, geostatistics interpolation method, Hoek-Brown criterion. Then, rock-mass characterization model was transformed slope numerical models, characteristics landslides were predicted combined with monitoring data simulation. Finally, pairing between potential-...

Based on Ježek method of computing the elastic-plastic buckling member under axial compressive load and bending moment, considering initial geometric imperfection, analytical expressions calculating ultimate about neutral axis with maximum moment inertia for an H-shaped flange outsides wrapped by carbon fibre are derived. Using finite element theory nonlinear buckling, impact imperfection steel analyzed numerical solutions bearing capacity obtained. By compared values (FEM), it shows that in...

Based on Ježek method of computing the elastic-plastic buckling member under axial compressive load and bending moment, considering initial imperfection, analytical expressions calculating ultimate about neutral axis with maximum moment inertia for a square steel tube are derived. Using finite element theory nonlinear buckling, impact by geometric imperfections analyzed numerical solutions bearing capacity obtained. By compared values (FEM), it shows that in this paper is valid. The results...

Based on Ježek method of computing the elastic-plastic buckling members under axial compressive load and bending moment, considering initial imperfection, analytical expressions calculating ultimate about neutral axis with maximum moment inertia for an H-shaped member a square steel tube are derived. Using finite element theory nonlinear buckling, impact by geometric imperfections analyzed numerical solutions bearing capacity obtained. By compared values (FEM), it shows that in this paper...

Combined with the finite element method (FEM) and field data of Shenyang Metro NTR engineering for pipe jacking process, variation surface deformation influence factors construction are systematically analyzed. The result is shown that curves lateral subsidence produced by process accord normal distribution put forward Peck .When top steel pipes jacked , develops rapidly rate larger. In addition grouting behind wall sequence all have a greater impact on layer.

Based on Ježek method of computing the elastic-plastic buckling member under axial compressive load and bending moment, considering initial geometric imperfection, analytical expressions calculating ultimate about neutral axis with maximum moment inertia for a square steel tube flange outsides wrapped by carbon fibre are derived. Using finite element theory nonlinear buckling, impact imperfection analyzed numerical solutions bearing capacity obtained. By compared values (FEM), it shows that...

At the design stage of a machine tool, how to accurately predict and analyze motion error linear axis system is difficult problem for designers. This research great significance optimize initial scheme tool improve geometric accuracy. A kinematic errors prediction accuracy improvement method guide rail based on assembly manufacturing analysis was proposed. Firstly, distribution law bolt preload under specific sequence revealed by finite element (FEA). Based probability parameters, statically...

The whole bearing compressive process under eccentric compression is analyzed for the further study of capacity GFRP tube filled with SHC（steel-reinforced high-strength concrete）columns subjected to compression. Based on finite strip method from plane cross-section assumption, computation program SHC columns formulated according existing retrofit theory and related technical procedures. relation curves load-deformation, as well effect concrete strength, slenderness ratio, eccentricity...

Based on Ježek method of computing the elastic-plastic buckling member under axial compressive load and bending moment, considering initial imperfection, analytical expressions calculating ultimate about neutral axis with maximum moment inertia for an H-shaped are derived. Using finite element theory nonlinear buckling, impact by geometric imperfections steel analyzed numerical solutions bearing capacity obtained. By compared values (FEM), it shows that in this paper is valid. The results...