Stability Analysis of Sheet Pile Walls by Discontinuity Topology Optimization

2012 ◽  
Vol 487 ◽  
pp. 500-505
Author(s):  
Cang Qin Jia ◽  
Qi Wu Huang ◽  
Bo Ru Xia ◽  
Gui He Wang
Keyword(s):  
Topology Optimization ◽  
Stability Analysis ◽  
Optimization Technique ◽  
Engineering Practice ◽  
The Novel ◽  
Sheet Pile ◽  
Good Accord ◽  
The Stability ◽  
Rotational Failure ◽  
Kinematic Approach

A kinematic approach based on the framework of limit analysis is applied for stability analysis of sheet pile walls. A rotational failure mechanism is used to computer safety of factor, and the topology optimization technique is employed in the stability analysis. The analyses generally yielded good accord with the results in many aspects of the sheet pile walls behavior. The novel implementation of upper bound method with discontinuity topology optimization is reliable and useful for engineering practice and design.

A New Approach to Popov Criterion for Stability Analysis of Nonlinear Control Systems

2012 ◽  
Vol 463-464 ◽  
pp. 1549-1552
Author(s):  
Ivan Svarc
Keyword(s):  
Stability Analysis ◽  
Nonlinear Systems ◽  
Nonlinear Control ◽  
Control Systems ◽  
Transfer Functions ◽  
Sufficient Conditions ◽  
Nonlinear Control Systems ◽  
Engineering Practice ◽  
The Stability ◽  
The Given

The Popov criterion for the stability of nonlinear control systems is considered. The Popov criterion gives sufficient conditions for stability of nonlinear systems in the frequency domain. It has a direct graphical interpretation and is convenient for both design and analysis. In the article presented, a table of transfer functions of linear parts of nonlinear systems is constructed. The tables includes frequency response functions and offers solutions to the stability of the given systems. The table makes a direct stability analysis of selected nonlinear systems possible. The stability analysis is solved analytically and graphically. Then it is easy to find out if the nonlinear system is or is not stable; the task that usually ranks among the difficult task in engineering practice.

scholarly journals Asymptotic Stability Analysis and Optimality Algorithm for Uncertain Neutral Systems with Saturation

2014 ◽  
Vol 2014 ◽  
pp. 1-14
Author(s):  
Xinghua Liu
Keyword(s):  
Stability Analysis ◽  
Asymptotic Stability ◽  
Sufficient Conditions ◽  
The Novel ◽  
Neutral Systems ◽  
Additive Decomposition ◽  
Decomposition Approach ◽  
Optimality Algorithm ◽  
The Stability ◽  
The Relationship

The certain and uncertain neutral systems with time-delay and saturating actuator are considered in this paper. In order to analyse and optimize the system, auxiliary functions are presented based on additive decomposition approach and the relationship among them is discussed. As the novel stability criterion, two sufficient conditions are obtained for asymptotic stability of the neutral systems. Furthermore, the paper gives the stability analysis algorithm and optimality algorithm to optimize the result. Finally, from the two-stage dissolution tank of solid caustic soda in a chemical plant, three numerical examples are implemented to show the effectiveness of the proposed method.

An optimization technique for national income determination model with stability analysis of differential equation in discrete and continuous process under the uncertain environment

2019 ◽  
Vol 53 (5) ◽  
pp. 1649-1674 ◽  
Author(s):  
Biswajit Sarkar ◽  
Sankar Prasad Mondal ◽  
Sun Hur ◽  
Ali Ahmadian ◽  
Soheil Salahshour ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Continuous Process ◽  
Optimization Technique ◽  
National Income ◽  
Significant Implication ◽  
Generalized Hukuhara Derivative ◽  
Fuzzy Environment ◽  
Generalized Hukuhara Difference ◽  
The Stability ◽  
Income Determination

The paper represents a variation of the national income determination model with discrete and continuous process in fuzzy environment, a significant implication in economics planning, by means of fuzzy assumptions. This model is re-recognized and deliberated with fuzzy numbers to estimate its uncertain parameters whose values are not precisely known. Exhibition of imprecise solutions of the concerned model is carried out by using the proposed two methods: generalized Hukuhara difference and generalized Hukuhara derivative (gH-derivative) approaches. Moreover, the stability analysis of the model in two different systems in fuzzy environment is illustrated. Additionally, different illustrative examples for optimization of national income determination model are undertaken with the constructive graph and table for convenience for clarity of the projected approaches.

scholarly journals Stability analysis and novel solutions to the generalized Degasperis Procesi equation: An application to plasma physics

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0254816
Author(s):  
S. A. El-Tantawy ◽  
Alvaro H. Salas ◽  
Castillo H. Jairo E.
Keyword(s):  
Stability Analysis ◽  
Elliptic Functions ◽  
Cnoidal Wave ◽  
The Novel ◽  
Weierstrass Elliptic Function ◽  
Wave Solutions ◽  
Maxwellian Plasma ◽  
Basic Equations ◽  
The Stability ◽  
Special Case

In this work two kinds of smooth (compactons or cnoidal waves and solitons) and nonsmooth (peakons) solutions to the general Degasperis-Procesi (gDP) equation and its family (Degasperis-Procesi (DP) equation, modified DP equation, Camassa-Holm (CH) equation, modified CH equation, Benjamin-Bona-Mahony (BBM) equation, etc.) are reported in detail using different techniques. The single and periodic peakons are investigated by studying the stability analysis of the gDP equation. The novel compacton solutions to the equations under consideration are derived in the form of Weierstrass elliptic function. Also, the periodicity of these solutions is obtained. The cnoidal wave solutions are obtained in the form of Jacobi elliptic functions. Moreover, both soliton and trigonometric solutions are covered as a special case for the cnoidal wave solutions. Finally, a new form for the peakon solution is derived in details. As an application to this study, the fluid basic equations of a collisionless unmagnetized non-Maxwellian plasma is reduced to the equation under consideration for studying several nonlinear structures in the plasma model.

scholarly journals Stability Analysis of Axisymmetric Concave Slopes Based on Two-Dimensional Limit Equilibrium Approach considering Additional Shear Resistance

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Xiao-ming Liu ◽  
Rui Zhang ◽  
Jie Han ◽  
Sha Chen
Keyword(s):  
Stability Analysis ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Iteration Algorithm ◽  
Engineering Practice ◽  
Two Dimensional ◽  
Spatial Effects ◽  
Practical Applications ◽  
Equilibrium Approach ◽  
The Stability

Axisymmetric concave slopes, one special type of three-dimensional (3D) slopes, may be encountered in mining and civil engineering practice. Analysis of 3D slopes is generally complex and mostly relies on complicated numerical simulations. This paper proposes an elastoplastic solution for determining the additional shear resistances due to spatial effects of axisymmetric concave slopes. By incorporating the extra antislide forces, this paper proposes a simplified two-dimensional (2D) limit equilibrium procedure for the stability analysis of axisymmetric concave slopes. Combined with an iteration algorithm, the procedure can obtain the factors of safety for axisymmetric concave slopes in a simple and efficient way. Comparisons of the results from the proposed method and the numerical software FLAC3D are performed to demonstrate the validity of the proposed method for practical applications. Finally, the effects of several key parameters on the stability of axisymmetric concave slopes are investigated through a parametric study.

How to design a more stable dental implant: A topology optimization approach

2021 ◽  
pp. 095441192110480
Author(s):  
Mohammad Reza Niroomand ◽  
Hamidreza Toutounchi ◽  
Sayedali Mousavi
Keyword(s):  
Topology Optimization ◽  
Bone Growth ◽  
Optimization Technique ◽  
Element Model ◽  
Influential Factors ◽  
The Body ◽  
Optimization Approach ◽  
Maximum Displacement ◽  
Mandibular Segment ◽  
The Stability

The body shape design is one of the most influential factors in the success of dental implants. This study presents a strategy to design the geometrical features of a threaded implant. The topology optimization technique is applied to identify appropriate spaces in the implant body to be removed for bone growth. The exact shape, position, and dimensions of the spaces are determined using a finite element model. This model consists of a mandibular segment, implant, abutment, and crown. During the optimization process, some grooves and holes are created in the implant by removing redundant materials. Bone growth into these spaces causes mechanical locking between the implant and surrounding bone. The smoothing process is performed following the optimization to remove stress concentration. The results indicate that this design strategy reduces the maximum displacement of the implant by approximately 20%. Moreover, a reduction in the implant’s volume and an increase in the contact area between the implant and bone are obtained. All mentioned issues would increase the stability and reduce the risk of implant loosening. Finally, using conventional production methods, the optimal implant was produced from titanium alloy to demonstrate the possibility of production of the proposed design.

scholarly journals Seismic stability analysis of rock slopes by yield design theory using the generalized Hoek-Brown criterion

2018 ◽  
Vol 149 ◽  
pp. 02026
Author(s):  
Mounir Belghali ◽  
Zied Saada
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Design Theory ◽  
Rock Slope ◽  
Numerical Solutions ◽  
Stability Study ◽  
Seismic Stability ◽  
Rock Slopes ◽  
The Stability ◽  
Kinematic Approach

The stability of rock slope is studied using the kinematic approach of yield design theory, under the condition of plane strain and by considering the last version of the Hoek-Brown failure criterion. This criterion, which is suitable to intact rock or rock mass highly fractured regarded as isotropic and homogeneous, is widely accepted by the rock mechanics community and has been applied in numerous projects around the world. The failure mechanism used to implement the kinematic approach is a log-spiral rotational mechanism. The stability analysis is carried out under the effects of gravity forces and a surcharge applied along the upper plateau of the slope. To take account of the effects of forces developed in the rock mass during the passage of a seismic wave, the conventional pseudo-static method is adopted. This method is often used in slope stability study for its simplicity and efficiency to simulate the seismic forces. The results found are compared with published numerical solutions obtained from other approaches. The comparison showed that the results are almost equal. The maximum error found is less than 1%, indicating that this approach is effective for analyzing the stability of rock slopes. The relevance of the approach demonstrated, investigations are undertaken to study the influence of some parameters on the stability of the slope. These parameters relate to the mechanical strength of the rock, slope geometry and loading.

scholarly journals Experimental Study on Stability Analysis of a Structure during Excavation beneath This Structure

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yichen Miao ◽  
Baoxian Liu ◽  
Changwu Liu ◽  
Zhile Shu ◽  
Haikuan Wu
Keyword(s):  
Experimental Study ◽  
Stability Analysis ◽  
Model Test ◽  
Scale Model ◽  
Engineering Practice ◽  
Underground Space ◽  
Strain Change ◽  
Concrete Building ◽  
The Stability ◽  
The Impact

In order to create more underground space, it was important to investigate the impact of excavation on the preexisting building. In this paper, a scale model test was conducted to analyze the stability of the structure during excavation. The model consisted of underpinning piles preinstalled in clay, with a reinforced concrete building placed on underpinning piles. The strain and settlement of the structure were observed to reveal the time settlement of columns and the time strain of beams, columns, and piles during excavation. The results showed that the strain change of beams was small, and strain values of columns were getting higher. And underpinning piles had great strain variations. They were of great significance to underpinning design and engineering practice.

Stability Analysis of the Nanjung Water Diversion Twin Tunnels based on Convergence Measurement

2019 ◽  
Vol 1 (1) ◽  
pp. 49-60
Author(s):  
Simon Heru Prassetyo ◽  
Ganda Marihot Simangunsong ◽  
Ridho Kresna Wattimena ◽  
Made Astawa Rai ◽  
Irwandy Arif ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Convergence Rate ◽  
Critical Strain ◽  
Convergence Rates ◽  
Strain Analysis ◽  
Water Diversion ◽  
Tunnel Face ◽  
Tunnel Stability ◽  
The Stability ◽  
Twin Tunnels

This paper focuses on the stability analysis of the Nanjung Water Diversion Twin Tunnels using convergence measurement. The Nanjung Tunnel is horseshoe-shaped in cross-section, 10.2 m x 9.2 m in dimension, and 230 m in length. The location of the tunnel is in Curug Jompong, Margaasih Subdistrict, Bandung. Convergence monitoring was done for 144 days between February 18 and July 11, 2019. The results of the convergence measurement were recorded and plotted into the curves of convergence vs. day and convergence vs. distance from tunnel face. From these plots, the continuity of the convergence and the convergence rate in the tunnel roof and wall were then analyzed. The convergence rates from each tunnel were also compared to empirical values to determine the level of tunnel stability. In general, the trend of convergence rate shows that the Nanjung Tunnel is stable without any indication of instability. Although there was a spike in the convergence rate at several STA in the measured span, that spike was not replicated by the convergence rate in the other measured spans and it was not continuous. The stability of the Nanjung Tunnel is also confirmed from the critical strain analysis, in which most of the STA measured have strain magnitudes located below the critical strain line and are less than 1%.

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