Novel approach to optimizing express–local metro train timetable considering multiple train stopping patterns

Providing effective Through Train Services (TTSs) faces challenges due to complex infrastructure conditions, train performances and passenger demands. To enhance TTSs between two different classes of urban rail transit lines with variations in train speed and capacity, we propose a multi-objective Integer Non-Linear Programming (INLP) model. This model maximizes passenger travel time savings and average train load utilization, and develops an integrated approach to simultaneously optimize the frequencies of through express trains and local trains, as well as the operation zones, stopping patterns and type selection of through trains. Additionally, a Non-Dominated Sorting Genetic Algorithm II is designed to solve the INLP model based on a simple test network and a real-world case from the Nanjing Subway. The unique benefits of our proposed method are demonstrated by a comprehensive compared with the Single Line Operation Mode and the all-stop plans under Through Operation Mode.

New subduction zones may initiate either in intra-oceanic setting or in the vicinity of rifted margins. At both sites, the requirement of subduction initiation is the efficient strain localization and sufficient in-situ external forcing to overcome the shear and bending resistance of the lithosphere. While the age-dependent negative buoyancy of the oceanic lithosphere is the greatest at the ocean-continent boundary and therefore, rifted margin should be more favorable sites for subduction initiation, the increasing mechanical coupling between the oceanic and continental domains and the coeval strengthening of the rifted margin have been suggested to limit subduction initiation along the ocean-continent boundary to the first few tens of million years after continental break-up. This, in particular, suggests that the duration of the transitional interval between rifting and plate convergence plays a crucial role in determining the location of subduction initiation.In this study, we investigated compression-induced subduction initiation in young and narrow oceanic basins, where the thermo-tectonic age of the rifted margin is low and thus, it is weak and more prone to strain localization. By using the I3ELVIS-FDSPM numerical code, we tested the duration of the plate motion reversal from rifting to convergence, and evaluated the role of the associated structural and thermo-rheological inheritance in controlling the location of subduction initiation. The models tracked the dynamic changes in the lithospheric strength and strain patterns, while the applied two-way coupling between the high-resolution 3D geodynamical and surface processes models allowed for the joint analysis of the crustal tectonics, thermal structure, melting, topography evolution, and the erosion-sedimentation processes.The results show that abrupt plate motion changes lead to ridge-inversion and subsequent intra-oceanic subduction initiation along the extinct spreading ridge, controlled by the inherited thermal- and melt-induced weakening effects of the shallow lithosphere-asthenosphere boundary. In contrast, when the transition between rifting and plate convergence exceeds a few million years, strain localization is linked to inherited lithospheric-scale weak zones, such as pre-existing suture zones underneath the continental margin, while the inherited thermal structure no longer exerts a substantial influence on the location of subduction initiation. These modeling inferences align with observations from natural subduction initiation sites, such as the Algerian margin and the eastern Japan Sea.

This study addresses the tectonic and mechanical significance of crustal‐scale strain and shear zone patterns in the South Indian Precambrian lithosphere. It is based on a tectonic map of the Dharwar craton derived from LANDSAT imagery, existing documentation, and our own field observations. We document the contrasted responses of the two main parts of the craton to late Archean (2.56–2.51 Ga) shortening. The old (>3 Ga) lithosphere of the Western Dharwar craton stabilized at 2.61 Ga underwent moderate shortening and strain localization along spaced shear zones. The Eastern Dharwar craton, rejuvenated by late Archean juvenile magmatic accretion, responded to shortening by flowing laterally against the Western Dharwar craton. Shortening operated without significant thickening because of the high buoyancy of the juvenile crust and the very low strength of its mantle lithosphere. The late Archean crustal‐scale shear zone network did not accommodate large displacements and only contributed to smoothing out of strain heterogeneities during the latest stages of flow. The shear zone pattern only reflects the symmetry of the regional finite strain field of a wide hot orogen. It does not result from terrain amalgamation but accompanies crustal flow and does not compare with those of modern active margins, which accommodate unidirectional transpression. Our analysis further suggests that the shear zones bounding the craton did not record large horizontal displacements during final assembly of Gondwana but rather transverse shortening and vertical extrusion.

A 3-D finite element method for non-isothermal sheet-forming processes

Application of geopolymer in synchronous grouting for reusing of the shield muck in silty clay layer

Optimization for operation scheme of express and local trains in suburban rail transit lines based on station classification and bi-level programming

An investigation of plastic flow localization patterns (waves) which are ordered in space and evolve with time has been performed for a wide range of metals and alloys. These waves are found to have the following basic features: the dependence of propagation rate on work hardening coefficient, dispersion law and scale effect. The possibility of addressing plastic flow localization as a self-organization process occurring in a deforming medium is considered. A set of equations appropriate for the description of local flow nuclei is discussed. Consideration is given to a change-over from one local strain pattern to another in accordance with the respective stages of flow. Proposed is a model for interpreting the large-scale periodicities exhibited by the distribution of localized strain nuclei.

An investigation of plastic flow localization patterns (waves) which are ordered in space and evolve with time has been performed for a wide range of metals and alloys. These waves are found to have the following basic features: the dependence of propagation rate on work hardening coefficient, dispersion law and scale effect. The possibility of addressing plastic flow localization as a self‐organization process occurring in a deforming medium is considered. A set of equations appropriate for the description of local flow nuclei is discussed. Consideration is given to a change‐over from one local strain pattern to another in accordance with the respective stages of flow. Proposed is a model for interpreting the large‐scale periodicities exhibited by the distribution of localized strain nuclei.

The influence of hydrogen embrittlement of the aluminum Al–4%Cu–0.2%Mg alloy on the parameters of localized plastic strain is studied. Digital speckle photography is used to visualize the localized strain patterns in the D1 alloy. The velocity of localized deformation bands as a function of the yield strength for nonhydrogenated and hydrogenated samples is found.

Investigation of the Z-binder role in progressive damage of 3D woven composites

Method development in interaction polymer chromatography

Exploring alternative bus operations strategies for adaptive and efficient transit systems in the face of disruptions

Laser Cladding is an additive manufacturing technology enabling to repair complex metallic components by removing the worn region and reconstructing locally the initial geometry. The aim of this work is to study the mechanical response of Inconel 718 repaired thin walls. More precisely, we perform an EBSD imaging and in-situ SEM tensile tests on specimen whose gauge section contains the interface between base material and repaired area. We observe the multiaxial strain patterns until failure at the grain level using a Digital Image Correlation method and superpose this pattern with the microstructure gradient induced by repair. The observations highlight a strain localization phenomenon in repaired structures mainly due to grain size effect.

Mixed stabilized finite element methods in nonlinear solid mechanics. Part III: Compressible and incompressible plasticity

The classic metaphyseal lesion (CML) is strongly associated with infant abuse, but the biomechanics responsible for this injury have not been rigorously studied. Radiologic and CT-pathological correlates show that the distal tibial CML always involves the cortex near the subperiosteal bone collar, with variable extension of the fracture into the medullary cavity. Therefore, it is reasonable to assume that the primary site of bone failure is cortical, rather than intramedullary. This study focuses on the strain patterns generated from finite element modeling to identify loading scenarios and regions of the cortex that are susceptible to bone failure. A geometric model was constructed from a normal 3-month-old infant's distal tibia and fibula. The model's boundary conditions were set to mimic forceful manipulation of the ankle with eight load modalities (tension, compression, internal rotation, external rotation, dorsiflexion, plantar flexion, valgus bending and varus bending). For all modalities except internal and external rotation, simulations showed increased cortical strains near the subperiosteal bone collar. Tension generated the largest magnitude of cortical strain (24%) that was uniformly distributed near the subperiosteal bone collar. Compression generated the same distribution of strain but to a lesser magnitude overall (15%). Dorsiflexion and plantar flexion generated high (22%) and moderate (14%) localized cortical strains, respectively, near the subperiosteal bone collar. Lower cortical strains resulted from valgus bending, varus bending, internal rotation and external rotation (8-10%). The highest valgus and varus bending cortical strains occurred medially. These simulations suggest that the likelihood of the initial cortical bone failure of the CML is higher along the margin of the subperiosteal bone collar when the ankle is under tension, compression, valgus bending, varus bending, dorsiflexion and plantar flexion, but not under internal and external rotation. Focal cortical strains along the medial margins of the subperiosteal bone collar with varus and valgus bending may explain the known tendency for focal distal tibial CMLs to occur medially. Further research is needed to determine the threshold of applied forces required to produce this strong indicator of infant abuse.