Article
Construction & Building Technology
Sayan Sirimontree, Suraparb Keawsawasvong, Chayut Ngamkhanong, Sorawit Seehavong, Kongtawan Sangjinda, Thira Jearsiripongkul, Chanachai Thongchom, Peem Nuaklong
Summary: This study presents a scheme for accurate and reliable predictions of tunnel stability based on an artificial neural network (ANN). Plastic solutions of unlined elliptical tunnels in sands are derived using numerical upper-bound and lower-bound finite element limit analysis, which are then used as the training dataset for an ANN model. The study comprehensively examines the impacts of several dimensionless parameters on the stability factor of shallow elliptical tunnels in sands, and provides a reliable and accurate safety assessment.
Article
Engineering, Geological
Fuquan Chen, Shanchu Luo, Fengwen Lai
Summary: This paper focuses on the trapdoor responses in cohesive-frictional materials above deep active layers and proposes new analytical solutions. Based on finite-element limit analyses (FELA), the failure mechanisms of a deep active trapdoor are studied. Three distinct failure modes are observed and analytical solutions are proposed to calculate the modified lateral earth-pressure coefficient and vertical stresses in soils. The proposed solutions are validated and their effectiveness is demonstrated through comparison and parametric study.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Mohammad Mojallal, Orang Farzaneh, Faradjollah Askari
Summary: This paper proposes a numerical method using the upper bound shakedown theorem to obtain the shakedown limit of strip footing under repeated loading. The role of unit weight of soil in the shakedown limit and the effect of repeated load on the reduction of bearing capacity of footing are investigated in several examples.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Materials Science, Multidisciplinary
Laura Ahmels, Daniel Dehtyriov, Enrico Bruder, Andrey Molotnikov
Summary: The study investigates the deformation behavior and evolution of strain distributions of flat metal sheets in the high-strain forming process of linear flow splitting (LFS) using experimental and numerical techniques. A new tracer gradient method for mapping material flow based on diffusional concentration gradients is proposed. The research shows that friction between rolls and sheet is a critical parameter in the modeling of the LFS process.
ADVANCED ENGINEERING MATERIALS
(2021)
Article
Engineering, Mechanical
F. Parrinello, I. Benedetti
Summary: A novel thermodynamically consistent cohesive-frictional model is proposed for analyzing interface degradation and failure in low-cycle fatigue problems. The model combines plasticity and damage mechanics and captures the evolution of damage and plasticity under external loads. The model accurately simulates the behavior of the interface under different loading conditions.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Geological
John P. Carter, Hai-Sui Yu
Summary: This paper presents a rigorous semi-analytical solution for the expansion of cavities from zero initial radius in cohesive-frictional soils with limited dilation, using the incremental velocity method introduced by R. Hill. The solution, based on the timescale of the elastic-plastic interface, provides insights into the limit pressure of cavity expansion in different types of material. A comparison is made between this solution and previous ones for cohesive-frictional soils with unlimited plastic dilation, highlighting the influence of limited plastic dilation on the cavity limit pressure.
Article
Automation & Control Systems
Lhoucine Boutrih, Lanouar Ben Ayed, Mohammed Nouari
Summary: Structures involving assembled materials such as titanium/composite are commonly used in the aeronautical industry due to their high mechanical properties, but machining difficulties are often encountered due to their poor machinability. A numerical model considering different phases of the assembly has been developed, which revealed that the cutting sequence is crucial in preventing interface delamination. The study also found two levels of cutting forces related to the ductile behavior of the titanium phase and the brittle behavior of the composite phase during the orthogonal cutting process.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Engineering, Multidisciplinary
Ankit Ankit
Summary: This study develops a new procedure for solving cohesive and frictional crack growth problems in quasi-brittle materials using the SBFEM, which models cohesive and contact tractions using linearised tractions and zero-thickness interface elements. A stress-based criterion is employed to determine crack propagation condition and direction effectively.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Dulpinit Noo-Iad, Jim Shiau, Weeraya Chim-Oye, Pitthaya Jamsawang, Suraparb Keawsawasvong
Summary: In this study, three efficiency factors were proposed to describe the bearing capacity effects of closely spaced footings using Terzaghi's traditional bearing capacity equation. The numerical analysis showed that the efficiency factors were significantly influenced by the internal frictional angle and the spacing ratio. Design charts were also produced to provide practical guidelines for foundation engineering practitioners.
Article
Engineering, Civil
Yao Xiao, Minghua Zhao, Rui Zhang
Summary: The article presents the seismic bearing capacity for strip footings above square voids in cohesive-frictional soils. Through numerical study using adaptive finite element limit analysis (AFELA), the upper bound (UB) and lower bound (LB) of the seismic bearing capacity for the strip footing are obtained, with relative errors within 8% or less. The results are presented in design tables and charts for designers and practicing engineers to use. The effects of void location, dimensionless strength ratio, soil internal friction angle, and horizontal seismic coefficient on the seismic bearing capacity are examined, and failure mechanisms and comparisons with previous static studies are discussed.
EARTHQUAKE SPECTRA
(2023)
Article
Computer Science, Interdisciplinary Applications
Seyed Mohamad Mirmoazen, Seyed Hamid Lajevardi, Seyed Mohammad Mirhosseini, Meghdad Payan, Reza Jamshidi Chenari
Summary: In this study, the lateral earth pressure on geosynthetic-reinforced retaining walls with an anisotropic granular backfill under strip footing loadings is evaluated using a combination of limit analysis theory, second order cone programming, and finite element method. It was found that the inherent anisotropy of the soil increases the coefficient of active earth pressure on the retaining structures.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Chemistry, Multidisciplinary
Yongge Zeng, Gaoqiao Wu
Summary: This study used an adaptive finite element limit analysis code to investigate the stability of dual tunnels in cohesive-frictional soil under surcharge loading and seismic action. Parametric studies were conducted, and strict upper and lower bound results with small relative errors were obtained. Design tables and failure patterns were provided for engineering design. The results showed that soil unit weight and void depth have a nearly linear effect on seismic bearing capacity. The dual tunnel system is vulnerable to seismic actions, and the stability of tunnels is further undermined by the adverse effects of seismic-caused interactions between adjacent tunnels.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Mechanical
Jianjun Li, Tianyu Chen, Tingting Chen, Zhong Yun, Xiaodong Xia
Summary: A finite element model was established to investigate the deformation of bimodal structured copper during scratch test, showing that bimodal nanostructures can achieve a lower coefficient of friction by adjusting the grain size and volume fraction of the hard and soft domains.
The study found that the heterogeneity of bimodal nanostructures can effectively restrain strain localization, leading to reduced coefficient of friction and a better balance of high strength and low COF.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Chemistry, Physical
A. Valverde-Gonzalez, E. Martinez-Paneda, A. Quintanas-Corominas, J. Reinoso, M. Paggi
Summary: This article presents a combined phase field and cohesive zone formulation for hydrogen embrittlement in metals, which resolves the polycrystalline microstructure. The model takes into account the hydrogen-microstructure interactions and explicitly captures the interplay between bulk fracture and intergranular fracture. Simulations in relevant case studies show the potential of the theoretical and computational formulation in capturing inter- and trans-granular cracking.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Mechanics
Lan Shang, Christophe Hoareau, Andreas Zilian
Summary: An electromechanical model for beam-like piezoelectric energy harvesters based on Reissner's beam theory is developed, capturing first-order shear deformation and large displacement/rotation. The model is extensible to investigate various piezoelectric energy harvesters and allows for two-way interaction between mechanical and electrical fields. Extensive numerical examples validate the model's accuracy and applicability in both linear and nonlinear regimes, demonstrating its ability to predict limit cycle oscillations in axial flow.
