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The purpose of this paper is to propose a universal, robust and efficient method to obtain a reliable initial guess solution for the one‐step finite element simulation.

In one‐step simulation, getting initial guess solutions effectively is essential to ensure the success of the non‐linear resolution in the implicit static solver and to speed up the convergence of the Newton‐Raphson iterations. A newly emerging mesh parameterization approach named As‐Rigid‐As‐Possible method, which is widely used in computer graphics, is proposed as an effective initial guess estimation method in this paper. It is almost an isometric parameterization and showing excellent area‐preserving capability than other state‐of‐the‐art approaches. Several numerical examples are provided to verify the validity and efficiency of the presented method.

Compared with the geometry mapping methods, the presented ARAP method shows its universality in handling types of workpieces whether they have quasi‐vertical walls or they are long and complicated. Complex 3D workpieces with many local convex and concave features can also be well handled without large element shape distortions. In contrast to the energy based mapping algorithm, the method presented in this paper does not need to predefine the boundary nodes which will introduce less distortion to the elements near the boundary.

This paper is the first to utilize the As‐Rigid‐As‐Possible mesh parameterization algorithm to obtain an initial guess for the one‐step simulation. The numerical experiments show that the approach is universal, robust and efficient and can be further utilized in the optimum blank design or blank shape optimization.

Claims that, although the use of adhesives in automated assembly is common, the use of structural adhesives is not so. Indeed, the use of structural adhesives can be termed a “new technology”. Offers advice on their use and concludes that the benefits outweigh the threat of failure.

MANY problems associated with aircraft investigations involve the accurate measurement of fluctuating fluid pressures. Various types of pickup exist from which choice may be made for this purpose. The suitability of a particular type for a specific application depends on the characteristics of the type and its associated electronic recorder. The fundamental requirements of fluctuating pressure pickups are discussed, and various types are described and typical examples of their application are given. Design data are derived based on experiments conducted on condenser type pickups, from which it is possible to design single diaphragm types for particular frequency and sensitivity requirements.

IT has long been conceded that production and research should go hand in hand in the Aircraft Industry, but the precept has often differed lamentably from practice. However, most large firms have in recent years been gradually extending their ordinary works testing equipment, both mechanical and physical, to include research into the properties of the materials of aircraft construction. Further, the expansion of the Royal Air Force from its decimated early post‐war condition has also revived an industry which scant orders had rendered practically moribund, so that most firms have been able to extend their facilities for aerodynamic research. The housing during the past year of the whole of the Fairey Aviation Company's research work under one roof is a most pleasing indication that, at least in the minds of private firms, the golden ideal of production is not going to flourish at the expense of the neglect of research.

The purpose of the paper is to describe the changes that were needed in an existing offline programming system (OLP) in order to produce heavy steel weldments.

The paper examines the changes needed in an OLP system in order to produce heavy steel weldments in a shipyard.

The paper finds that the new requirements given for the production of hatch coaming lead to a fundamentally change in the design of the OLP system; it is possible to automate the welding of heavy steelplates, but the savings in this process are not always as planned.

It is not clear that the added complexity makes for a better software system. Sometimes a split into two programs makes the design of the programs more simple.

The paper shows how manipulators can be used in a new way to increase the welding quality at a robot installation in a shipyard.

Stephen McClelland reports on how one man has modified surface‐mount machines, and achieved remarkable performances as a result.

Mesh Parameterization is central to reverse engineering, tool path planning, etc. This work synthesizes parameterizations with un-constrained borders, overall minimum angle plus area distortion. This study aims to present an assessment of the sensitivity of the minimized distortion with respect to weighed area and angle distortions.

A Mesh Parameterization which does not constrain borders is implemented by performing: isometry maps for each triangle to the plane Z = 0; an affine transform within the plane Z = 0 to glue the triangles back together; and a Levenberg–Marquardt minimization algorithm of a nonlinear F penalty function that modifies the parameters of the first two transformations to discourage triangle flips, angle or area distortions. F is a convex weighed combination of area distortion (weight: α with 0 ≤ α ≤ 1) and angle distortion (weight: 1 − α).

The present study parameterization algorithm has linear complexity [𝒪(n), n = number of mesh vertices]. The sensitivity analysis permits a fine-tuning of the weight parameter which achieves overall bijective parameterizations in the studied cases. No theoretical guarantee is given in this manuscript for the bijectivity. This algorithm has equal or superior performance compared with the ABF, LSCM and ARAP algorithms for the Ball, Cow and Gargoyle data sets. Additional correct results of this algorithm alone are presented for the Foot, Fandisk and Sliced-Glove data sets.

The devised free boundary nonlinear Mesh Parameterization method does not require a valid initial parameterization and produces locally bijective parameterizations in all of our tests. A formal sensitivity analysis shows that the resulting parameterization is more stable, i.e. the UV mapping changes very little when the algorithm tries to preserve angles than when it tries to preserve areas. The algorithm presented in this study belongs to the class that parameterizes meshes with holes. This study presents the results of a complexity analysis comparing the present study algorithm with 12 competing ones.

The 3D dynamic clothing simulation is widely used in computer-added garment design. Collision detection and response are the essential component and also the efficiency bottleneck in the simulation. The purpose of this paper is to propose a high efficient collision detection algorithm for 3D clothing-human dynamic simulation to achieve both real-time and virtually real simulation effects.

The authors approach utilizes the offline data learning results to simplify the online collision detection complexity. The approach includes two stages. In the off-line stage, model triangles with most similar deformations are first, partitioned into several near-rigid-clusters. Clusters from the clothing model and the human model are matched as pairs according to the fact that they hold the potential to intersect. For each cluster, a hierarchical bounding box tree is then constructed. In the on-line stage, collision detection is checked and treated parallelly inside each cluster pairs. A multiple task allocation strategy is proposed in parallel computation to ensure efficiency.

Reasonably partitioning the 3D clothing and human model surfaces into several clusters and implementing collision detection on these cluster pairs can efficiently reduce the model primitive amounts that need be detected, consequently both improving the detection efficiency and remaining the simulation virtual effect.

The current methods only utilize the dynamic clothing-human status; the authors algorithm furthermore combines the intrinsic correspondence relationship between clothing and human clusters to efficiently shrink the detection query scope to accelerate the detection speed. Moreover, partitioning the model into several independent clusters as detection units is much more profitable for parallel computation than current methods those treat the model entirety as the unit.

The calibration is a key but cumbersome process for 3D body scanning using multiple depth cameras. The purpose of this paper is to simplify the calibration process by introducing a new method to calibrate the extrinsic parameters of multiple depth cameras simultaneously.

An improved method is introduced to enhance the accuracy based on the virtual checkerboards. Laplace coordinates are employed for a point-to-point adjustment to increase the accuracy of scanned data. A system with eight depth cameras is developed for full-body scanning, and the performance of this system is verified by actual results.

The agreement of measurements between scanned human bodies and the real subjects demonstrates the accuracy of the proposed method. The entire calibration process is automatic.

A complete algorithm for a full human body scanning system is introduced in this paper. This is the first publically study on the refinement and the point-by-point adjustment based on the virtual checkerboards toward the scanning accuracy enhancement.