Application of Solid Works' Parametric Modeling Method in Tunnel's Finite Element Numerical Simulation Analysis

A Reverse Engineering (RE) method for parametric modelling is presented in this paper. According to this method laser scanning data are processed by means of an algorithm and a parametric geometry is produced. The algorithm generates a spline used as a driving curve for a 2D profile, both approximated from the point cloud data, with the final geometry being produced through with a sweep based technique. The method was applied to digitize a commercial product, a bottle, and the geometry was reconstructed at high accuracy and surface quality. Finally the results of the proposed method were compared with auto surfacing from *.stl files and with surfaces generated by means of sweep commands without converting curves to splines.

A parametric 3D geological modeling method considering stratigraphic interface topology optimization and coding expert knowledge

Electromagnetic (EM) parametric modeling of microwave filters is a significant research direction in the microwave filter design and optimization field. The parametric model aims to predict the EM response (such as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$S$</tex>-parameters) based on the input geometrical parameters, so it is crucial to establish an accurate and effective parametric model. In this paper, a parametric modeling method that combines artificial neural network (ANN) with coupling matrix (CM) is applied to the parametric modeling of a fifth-order filter. A center-out optimization algorithm combined with phase de-embedding is proposed to extract CM. Due to the strong continuity of the extracted coupling parameters, the established parametric model can be valid in a wider geometrical neighborhood.

Stepwise Application of BIM-based Parametric Modeling to Tapered Slip-Form System

Aiming at the saddle of transmission line material ropeway, the structural design of components was carried out with the combination of 3D design software. Parametric modeling method was adopted to carry out the modeling of components with different structural parameters. The stress status of components of saddle was analyzed, the design load of components was proposed, and the strength of the designed components was checked through finite element simulation analysis. The results show that the components can meet the requirements of structural strength. The proposed method can realize parametric modeling of solid model and effectively improve the design efficiency of material ropeway.

A new method is described for calculating flare combustion efficiency (CE) and destruction and removal efficiency (DRE) using a numerical parametric model. The method combines key variables that affect flare performance including the flare vent gas net heating value (NHV), flare design, flow rate, exit velocity, and inert gas composition, alongside the environmental influence of crosswind speed. Each effect is characterized using a parametric model derived from experimental testing data and computational fluid dynamics (CFD). The inclusion of CFD allows the model to be extended into the high-wind conditions that cannot be adequately controlled for in empirical testing yet represent some of the most challenging conditions in which to maintain good combustion. This new parametric model method (PMM) is coupled with ultrasonic flowmeters from which the molecular weight and net heating value of the flare gas can be derived using the vent gas speed of sound measurement. In doing so, this method provides a reliable continuous flare combustion efficiency measure that can be deployed at scale with minimum hardware updates. The system was verified using an extractive sampling method with tests conducted on three full-scale industrial flares including non-assisted, single-arm pressure-assisted, and multi-arm pressure-assisted flare designs. A total of seventy valid test points were carried out with varying flow rate and flare gas heating value, covering a CE range from 46–100%. The uncertainty of the method was assessed using both traditional error propagation and Monte Carlo methodology. The results from the new method agree with the extractive method to within 0.8% in the ≥98% DRE region where flares are expected to operate to limit the impacts of flaring as a source of methane as a greenhouse gas. Uncertainty analysis revealed that the larger DRE discrepancy for DRE ≤ 98% correlates to the measurement uncertainties for both methods.

This case report describes a successful post‐tumour surgical reconstruction of a complete maxilla resection in a 62‐year‐old man, using an equine bone block [pre‐shaped using computer aided design/computer aided manufacturing (CAD/CAM) procedure] as grafting material. Computerised tomographic scans taken 5 months after the reconstructive surgery showed good reconstruction and dimensional augmentation of the lost bone. One year after surgery, the patient showed a great improvement in the emergence profile of the middle part of the face. The use of an equine bone block, pre‐shaped using CAD/CAM system, for alveolar ridge reconstruction, seems to be a valuable alternative to autograft. This technique could significantly shorten the actual surgical procedure for the patient and may result in a better fit of the graft than chair‐side preparation may allow.

Dynamic parametric modeling-based model updating strategy of aeroengine casings

The relative Ma number from rotor outlet is often quite large in high pressure turbine, especially in vaneless counter rotating turbine. Therefore, it is necessary that appropriate blades are adopted for high Ma working circumstances. In this paper, 13 design parameters are firstly chosen through analysis of the key factors that affecting the high Ma turbine performance. Then the non-uniform rational B spline method is employed to parameterize the model of turbine blade, and made the dynamic parameters of key geometric parameters associate. Furthermore, a parametric modeling method is developed for high Ma turbine cascade. Later, the method is applied to design a big bend angle and high Ma turbine blade used for a counter rotating turbine of VCE. Simulations are carried out to verify the modeling and the results prove that design demands under both working patterns can be satisfied, which implies that the blades modelling method developed in this paper is appropriate for high Ma turbine blades.

To further improve the quality of parts in metal 3D printers, it is necessary to optimize the structure and study the performance of their gas circulation filtration systems. First, we used the parametric modeling method to complete the formed cavity modeling. We then optimized the design of the air inlet structure of the formed cavity using the moldflow simulation method, and finally, we evaluated the optimized design results through assembly experiments and measurements of the molded parts’ components. The combination of parametric modeling and moldflow simulation methods produced a high modeling efficiency and had a good effect on the optimized design of the gas circulation filtration systems. After optimizing the design, the turbulence intensities and distribution areas of the formed cavities were reduced. During the 3D printing of the curved guide plate, the plane of the guide plate holder was inclined 55° relative to the machining datum plane, which improved the form quality. The 3D printed curved guide plate closely matched the inlet end of the printer’s air duct, and the upper guide plate was fixed at a suitable position using screws. The niobium contents of the parts formed by the guide plate in Design 2 were low, which lays a foundation for the 3D printing of high-performance metal parts.

In this paper, a 3D human body meshed model with low resolution is obtained by parametric digital human modeling, but the meshed surface is not smooth enough to meet the requirements of practical application. To achieve the smoothing effect of the geometric model of digital human body, this paper proposes a mesh-smoothing method of 3D human model based on Sqrt3 subdivision algorithm. Experiment shows that this method applies to the multicurvature mesh body model based on parametric modeling method and achieves good results. The method is simple, efficient and of well-reserved feature.

Height-diameter relationships are of critical importance in tree and stand volume estimation. Stand description, site quality determination and appropriate forest management decisions originate from reliable stem height predictions. In this work, the predictive performances of height-diameter models developed for Taurus cedar (Cedrus libani A. Rich.) plantations in the Western Mediterranean Region of Turkey were investigated. Parametric modeling methods such as fixed-effects, calibrated fixed-effects, and calibrated mixed-effects were evaluated. Furthermore, in an effort to come up with more reliable stem-height prediction models, artificial neural networks were employed using two different modeling algorithms: the Levenberg-Marquardt and the resilient back-propagation. Considering the prediction behavior of each respective modeling strategy, while using a new validation data set, the mixed-effects model with calibration using 3 trees for each plot appeared to be a reliable alternative to other standard modeling approaches based on evaluation statistics regarding the predictions of tree heights. Regarding the results for the remaining models, the resilient propagation algorithm provided more accurate predictions of tree stem height and thus it is proposed as a reliable alternative to pre-existing modeling methodologies.

Lower resolution is the main shortcoming for geometrical model. Mesh smoothing is a basic method for turning a coarse and lower resolution model into a smooth one. The paper proposed a mesh smoothing method for parameterized geometrical body model based on the Loop subdivision. A smooth surface can be expressed with a lot of subdivision control meshes that has higher resolution with mesh subdivision rules. It can effectively avoid the shortcomings of coarser and lower resolution of parameterized geometrical model. Experiment shows that the method is meaningful for the geometrical body model based on parameterized modeling method and can produce multi-curvature mesh surface. It is simple, efficient and can preserve the features of the original model.

Simplified models are widely applied in finite element computations regarding mechanical and structural problems. However, the simplified model sometimes causes many deviations in the finite element analysis (FEA) of structures, especially in the non-designed structures which have undergone unknowable deformation features. Hence, a novel FEA methodology based on the parametric model by approximating three-dimensional (3D) feature data is proposed to solve this problem in the present manuscript. Many significant and effective technologies have been developed to detect 3D feature information accurately, e.g., terrestrial laser scanning (TLS), digital photogrammetry, and radar technology. In this manuscript, the parametric FEA model combines 3D point clouds from TLS and the parametric surface approximation method to generate 3D surfaces and models accurately. TLS is a popular measurement method for reliable 3D point clouds acquisition and monitoring deformations of structures with high accuracy and precision. The B-spline method is applied to approximate the measured point clouds data automatically and generate a parametric description of the structure accurately. The final target is to reduce the effects of the model description and deviations of the FEA. Both static and dynamic computations regarding a composite structure are carried out by comparing the parametric and general simplified models. The comparison of the deformation and equivalent stress of future behaviors are reflected by different models. Results indicate that the parametric model based on the TLS data is superior in the finite element computation. Therefore, it is of great significance to apply the parametric model in the FEA to compute and predict the future behavior of the structures with unknowable deformations in engineering accurately.

A hybrid finite element and extended transfer matrix method for the dynamic modeling of fluid-conveying pipeline with breathing cracks