Animating an articulated 3D character currently requires manual rigging to specify its internal skeletal structure and to define how the input motion deforms its surface. We present a method for ...animating characters automatically. Given a static character mesh and a generic skeleton, our method adapts the skeleton to the character and attaches it to the surface, allowing skeletal motion data to animate the character. Because a single skeleton can be used with a wide range of characters, our method, in conjunction with a library of motions for a few skeletons, enables a user-friendly animation system for novices and children. Our prototype implementation, called Pinocchio, typically takes under a minute to rig a character on a modern midrange PC.
Large slow rock-slope deformations, including deep-seated gravitational slope deformations and large landslides, are widespread in alpine environments. They develop over thousands of years by ...progressive failure, resulting in slow movements that impact infrastructures and can eventually evolve into catastrophic rockslides. A robust characterization of their style of activity is thus required in a risk management perspective. We combine an original inventory of slow rock-slope deformations with different PS-InSAR and SqueeSAR datasets to develop a novel, semi-automated approach to characterize and classify 208 slow rock-slope deformations in Lombardia (Italian Central Alps) based on their displacement rate, kinematics, heterogeneity and morphometric expression. Through a peak analysis of displacement rate distributions, we characterize the segmentation of mapped landslides and highlight the occurrence of nested sectors with differential activity and displacement rates. Combining 2D decomposition of InSAR velocity vectors and machine learning classification, we develop an automatic approach to characterize the kinematics of each landslide. Then, we sequentially combine principal component and K-medoids cluster analyses to identify groups of slow rock-slope deformations with consistent styles of activity. Our methodology is readily applicable to different landslide datasets and provides an objective and cost-effective support to land planning and the prioritization of local-scale studies aimed at granting safety and infrastructure integrity.
The uplift of the Tianshan and Pamir Mountains/Areas are caused by active intracontinental tectonic movements. The dynamic mechanism is controversial and has aroused great interest among scholars. In ...this study, we investigate the present three‐dimensional (3‐D) crustal deformation in the Tianshan and Pamir areas from multi‐geodetic observations from 2002 to 2021. The continuous water deficit throughout Tianshan and Pamir locates mainly in glacier‐covered areas, at a total rate of −0.8 cm w.e./yr, inducing spatial surface uplifting at rates of ∼0.2–0.5 mm/yr. These Global Positioning System (GPS)‐derived velocities in the vertical deformation of the Tianshan and Pamir were corrected based on surface elastic loading models and the Gravity Recovery and Climate Experiment Follow‐On (GRACE/GFO)‐inferred hydrological loading deformation, and interpolated using the GPS imaging method for a higher 3‐D crustal deformation spatial resolution. In conclusion, surface hydrology is one of the driven factors affecting the regional vertical velocity field observed by GPS. The kinematic crustal shortening and vertical tectonic uplift are integrated within different blocks, which illustrate the contemporary dynamics throughout the Tianshan and Pamir. The relevant spatial characteristics between the 3‐D crustal deformation and dynamic tomography along the Tianshan indicate that the relatively weaker lithosphere beneath the central Tianshan is subject to strong compression, which induces the present‐day crustal uplift.
Plain Language Summary
The mountain building of Tianshan and its forelands are the remote effect of collision between the Indian and Eurasian plates. As a typical region with intracontinental plate collisions, the Tianshan mountains have complex orogenic processes and geological structures. In this study, multi‐source geodetic observations are used to quantify the three‐dimensional (3‐D) crustal deformation in this region and its surroundings. The integrated surface elastic loading models and GRACE/GFO observations are used to modify the surface elastic loads of vertical land deformation from the GPS coordinate time series spanning from 2002 to 2021. We perform a detailed analysis of the intradecadal fluctuations of the GPS and GRACE/GFO observations. The GPS imaging has been adopted to interpolate 3‐D velocity vectors and tectonic deformation to identify the crustal deformation of Tianshan and Pamir. We compare the observed 3‐D crustal deformation with the dynamic tomography, which could provide a better understanding of the possible mechanisms of crustal uplift along the Tianshan.
Key Points
The variation of surface hydrological load induce crustal uplift in the Tianshan and its surroundings constrained by GRACE/GFO mascons
The imaged crustal deformation provides three‐dimensional characteristic in kinematics and dynamics throughout the Tianshan and Pamir
The weaker lithosphere beneath the central Tianshan is subject to strong compression that contributes to the tectonic uplift of Tianshan
The deformation problem of elasticity theory with regard to nonlinear deformations is examined. The expressions of deformations through displacements in the orthogonal curvilinear coordinate system ...are recorded. The relations for finite deformations in cylindrical and polar coordinate systems are derived. Physical relations for finite deformations and corresponding generalized stresses are recorded.
This paper proposes a method for calculating limiting deformations under conditions of localized deformation during tensile testing. The method for calculating limiting deformations was used to ...construct plasticity diagrams under conditions of strain localization under uniaxial tension. The plasticity diagram is one of the material functions that forms the technological map of the material. The plasticity diagram displays the properties of a material depending on the degree of deformation and the stress state scheme. According to the studies carried out in this work, it was established that the critical increase in plasticity with increasing stress state indicator is explained by the influence of three factors: the strain gradient, the history of deformation and the third invariant of the stress tensor. The obtained dependencies make it possible to construct plasticity diagrams for materials whose destruction is preceded by localized deformation in the form of a "neck". This work establishes the quantitative influence of these three factors on the magnitude of the limiting deformations of a sample stretched to the point of failure. Application plasticity diagrams constructed using the proposed methods for cold plastic deformation processes, depending on the type of deformation path and the features of metal rheology, clarifies the value of the used plasticity resource of the metal, which allows to reduce the number of defective products for processes whose modes are calculated according to limit deformations.
We give L2-bounds on the change in the complex projective structure on the boundary of conformally compact hyperbolic 3-manifold with incompressible boundary after drilling short geodesics. We show ...that the change is bounded by a universal constant times the square root of the length of the drilled geodesics. While L∞-bounds of this type where obtained in 7, our bounds here do not depend on the injectivity radius of the boundary.
Photodeformable liquid crystal polymers (LCPs) that adapt their shapes in response to light have aroused a dramatic growth of interest in the past decades, since light as a stimulus enables the ...remote control and diverse deformations of materials. This review focuses on the growing research on photodeformable LCPs, including their basic actuation mechanisms, the various deformation modes, the newly designed molecular structures, and the improvement of processing techniques. Special attention is devoted to the novel molecular structures of LCPs, which allow for easy processing and alignment. The soft actuators with various deformation modes such as bending, twisting, and rolling in response to light are also covered with the emphasis on their photo‐induced bionic functions. Potential applications in energy harvesting, self‐cleaning surfaces, sensors, and photo‐controlled microfluidics are further illustrated. The existing challenges and future directions are discussed at the end of this review.
Photodeformable azobenzene‐containing liquid crystal polymers (LCPs) offer the advantage of generating 3D movements under irradiation, thus becoming attractive candidates for diverse applications. Recent developments in photodeformable LCPs are presented, including various photodeformations with emphasis on bionic functions, molecular structure design strategies, and improvement of processing techniques. Finally, future developments and possible strategies to unsolved challenges are provided.
The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is the first and only one on the Virtual Fields Method, a recent technique to ...identify materials mechanical properties from full-field measurements. It contains an extensive theoretical description of the method as well as numerous examples of application to a wide range of materials (composites, metals, welds, biomaterials etc.) and situations(static, vibration, high strain rate etc.). Finally, it contains a detailed training section with examples of progressive difficulty to lead the reader to program the VFM. This is accompanied with a set of commented Matlab programs as well as with a GUI Matlab based software for more general situations.
The possible emergence of a localized buckled configuration for a simple supported linear elastic beam on an elastic foundation subject to axial compression is analyzed numerically. Beams on a ...softening foundation and, for comparison purposes, beams on a linear elastic foundation are considered. The critical bifurcation mode involves periodic lateral displacements for both foundations. Calculations are carried out for imperfections that can have a component in the shape of the critical periodic bifurcation mode as well as a component with a localized shape. For beams on a softening foundation, the buckled configuration obtained in the calculations depends on the magnitudes of the periodic and localized imperfection components: (i) for a wide range of imperfections, a rather abrupt growth of localized lateral displacements occurs after a load maximum, even if the imperfection magnitudes are such that the critical periodic mode is suppressed; or (ii) if the magnitude of the periodic imperfection component is sufficiently large, the buckled configuration with a localized imperfection involves lateral displacements that are oscillatory but not periodic. For beams on a linear elastic foundation, a calculation with a sufficiently large magnitude localized imperfection gives a localized buckled configuration under increasing load. For beams on both types of foundation, the main features of the lateral displacements in the localized buckled configuration are similar, for example, involving both positive and negative lateral displacements even if the localized imperfection only involves non-negative deflections.
•A beam on a softening foundation with periodic and localized imperfections.•A localized buckled shape can occur by a bifurcation after a load maximum.•A localized buckled shape can occur without any periodic imperfection.•A large periodic imperfection acts to suppress emergence of the localized shape.•A localized buckled shape can develop with no softening under increasing load.
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