Article
Computer Science, Interdisciplinary Applications
J. Triller, R. Immel, L. Harzheim
Summary: This paper extends the DiESL method to topology optimization using the SIMP approach, and tests it on the problem of a rigid pole colliding with a simple beam. The results show a significant improvement compared to the standard ESL method.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Computer Science, Interdisciplinary Applications
Mathias Stolpe, Nicola Pollini
Summary: The Equivalent Static Loads (ESL) algorithm for nonlinear static response structural optimization has been modified to improve convergence towards designs satisfying first-order optimality conditions. The modifications involve incorporating first-order estimates of the equivalent static loads in the sub-problems and stabilizing the algorithm through a trust-region approach. The practical convergence properties of the original and modified algorithms are assessed through numerical experiments on a set of reproducible structural size optimization problems. The results demonstrate the proposed algorithm's capability to numerically find optimized designs that satisfy first-order optimality conditions with moderate computational resources.
ADVANCES IN ENGINEERING SOFTWARE
(2023)
Article
Computer Science, Interdisciplinary Applications
Min-Ho Jeong, Sang-Ok Park, Gyung-Jin Park
Summary: The equivalent static loads method (ESLM) is a structural optimization method that can consider nonlinear and dynamic responses. It has been used in various structural optimization disciplines such as size, shape, and topology optimizations. However, the existing ESLM has a limitation of considering only one finite element model. This study aims to expand ESLM to multi-model optimization and discusses its performance using size and topology optimization examples.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Engineering, Manufacturing
Subodh C. Subedi, Ahmad Shahba, Mythili Thevamaran, Dan J. Thoma, Krishnan Suresh
Summary: In this study, a novel method for the design of support structures in laser powder bed fusion (LPBF)-based metal additive manufacturing is proposed. By extracting the equivalent static load (ESL) from transient simulation results, the size of support structures is optimized to minimize material and time consumption. Numerical experiments and sample fabrication validate the effectiveness of this method.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Multidisciplinary
Mustafa Al-Bazoon, Jasbir S. Arora
Summary: This paper introduces a new computational procedure for optimizing structures under dynamic loads. By transforming dynamic loads into equivalent static loads and utilizing metaheuristic optimization algorithms, the static response optimization problem with discrete design variables can be solved. However, it is found that ESL cycles cannot converge to the final design, thus original dynamic loads need to be used in the optimization process after several ESL cycles.
OPTIMIZATION AND ENGINEERING
(2022)
Article
Mechanics
Yijae Choi, Wonmo Kang, Jaemin Moon, Chang -Wan Kim
Summary: Sandwich composite structures under dynamic loads were optimized using the equivalent static load method. The ESLM achieved a convergence rate 24 times faster than the conventional method.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Ting-ting Ma, Lin Zhao, Teng-fei Ji, Te Tang
Summary: Wind load is an important design consideration for large-span structures, especially for openable structures with varying aerodynamic configurations and structural dynamics. This study evaluated the wind-induced response and equivalent static wind loads (ESWLs) of a large-span truss roof with rotatable roof structures under closed and open working states through wind-tunnel tests, finite element modeling, dynamic response analysis, and aeroelastic model tests. Four types of ESWL calculation methods were compared, and it was found that the cantilever structures in the open roof state experienced a significant drop in fundamental frequency and larger wind-induced response compared to the closed state. The displacement-related wind-induced vibration factor method showed the best agreement with the transient analysis results and is recommended for wind load equivalence in this study.
THIN-WALLED STRUCTURES
(2022)
Article
Engineering, Civil
Zekang Wang, Xiaohong Wang, Heng Zhao, Bo Chen, Qingshan Yang
Summary: Wind-induced response, spectrums of the modal generalized force, and equivalent static wind loads (ESWLs) of railway station canopies with single-span and three-span frame are investigated. The results show that the first mode dominates horizontal displacements and frame column stresses, and the second mode dominates vertical displacements and frame beam stresses of the canopy frames. The research proposes simplified mean wind dynamic pressure coefficients and the generalized modal force spectrum formula for different canopy spans, opening widths, and building height ratios, based on wind tunnel test results. Combining wind-induced response characteristics and the analysis method of universal ESWLs, the ESWLs are derived as the superposition of the peak inertia forces of the two dominating modes, ensuring the accuracy of nodal displacements and member stresses calculation.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Mechanical
Sang-ok Park, Wook-Han Choi, Gyung-Jin Park
Summary: Viscoelastic material is widely used in automotive structures for its excellent vibration-damping characteristics and appropriate stiffness. The material properties of viscoelastic material are dependent upon time, temperature, and loading path, which need to be considered in structural optimization. The Equivalent Static Loads Method (ESLM) is a practical structural optimization method for considering the characteristics of viscoelastic material.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING
(2021)
Article
Engineering, Civil
M. H. Huang, Y. L. Lo
Summary: This research aims to evaluate wind loads for all-target structural responses via only a few numbers of load distributions, and the proposed method shows fair consistencies and more realistic distributions in values.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2021)
Article
Engineering, Marine
Harsha Cheemakurthy, Zuheir Barsoum, Magnus Burman, Karl Garme
Summary: Lightweight ice-class vessels have the potential to increase payload capacity during ice periods and match energy consumption with non-ice-class vessels during ice-free periods. This study focuses on analyzing different lightweight hull structures for ice interactions, particularly in the quasi-static loading phase. Parametric investigations using the finite element method show that stiffened sandwich structures are the most favorable concept, offering a balance between light weight and high gross tonnage. Further research on material differences and structural parameters provide insights into creating viable lightweight variants for ice-going hulls.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Mechanical
Nicola A. Nodargi, Paolo Bisegna
Summary: A static limit analysis approach is proposed for assessing the collapse capacity of axisymmetric masonry domes subject to horizontal forces. The approach is based on the classical statics of shells and involves a unique computational strategy to determine collapse multiplier, incipient collapse mechanism, and expected crack pattern. The method is validated through convergence analysis, experimental results, and parametric analyses, showing reliability for estimating the pseudo-static seismic resistance of masonry domes, with an application to the central dome of the Taj-Mahal.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Chemical
Aviner Shreiber, Dmitry Portnikov, Haim Kalman
Summary: Single particle compression and impact tests were used to measure various parameters and analyze the relationships between compression force, projected area, and hardness. The study found that the applied force during impact was similar to the static compression force within a certain range of impact velocities. A semi-empirical model was developed to estimate the percentage of total kinetic energy required for surface and particle deformation.
Article
Engineering, Aerospace
Lei Wang, Yaru Liu, Xiaojun Wang, Zhiping Qiu
Summary: Due to the prevalence of multi-source uncertainties in practical engineering, reliability-based design optimization for structural dynamics is of great importance and significance. However, it has been rarely considered in topology optimization compared to size and shape optimization, mainly due to the lack of reasonable uncertainty cognition and the difficulty in solving sensitivity solutions for reliability constraints calculated from dynamic characteristics. Thus, this study proposes a new design strategy that combines the equivalent static loads algorithm with the set-theoretical convex method for dynamic response topology optimization under convex reliability constraints.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Mechanics
Zhijie Huang, Wensu Chen, Hong Hao, Zuyu Chen, Thong M. Pham, Tung T. Tran, Mohamed Elchalakani
Summary: The study conducted tests on GPC beams reinforced with BFRP bars under static and impact loads, revealing flexural failure mode under static load and combined flexure-shear failure mode under impact load, with additional static loading to examine residual capacities. Numerical models were also developed and used for parametric simulations, demonstrating a shift in failure mode from flexure-governed to punching-shear-governed with increased impact velocity.
COMPOSITE STRUCTURES
(2021)