Comparison of numerical approaches for structural response analysis of passenger ships in collisions and groundings

Historic timber structures forming vaulted roofs of public and ecclesiastical buildings are present worldwide. The structural response of these constructions is usually governed by the structural performance of the joints, the interaction between the timber structure and the masonry parts, and the current condition of both joints and timber members. At present, numerical approaches, such as finite element method-based approaches are well-established tools for investigating the global response of complex historic structures. Using a FE-based software package, the authors developed a numerical model of a portion of an existing historic vaulted timber structure, which is part of the roof of the Cathedral of Ica in Peru, considering the in-plane semi-rigid response of the planked arches in the elastic range. For this purpose, the rotational and shear stiffness of the joints and the properties of the materials, which are assumed in good conditions, are calibrated by comparing the numerical outputs with experimental results available in literature. The aim of the work presented here is to compare the response of the same vault assuming either continuous (planks continuously connected) or discontinuous arches (modelling of the semi-rigid response of the joints which connect the planks together).

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Analytical investigation of nonlinear heave-coupled response of tension leg platform

Proceedings of the Institution of Mechanical Engineers Part M Journal of Engineering for the Maritime Environment ◽

10.1177/1475090218776430 ◽

2018 ◽

Vol 233 (3) ◽

pp. 699-713

Author(s):

Mohammad Reza Tabeshpour ◽

Reza Hedayatpour

Keyword(s):

Degrees Of Freedom ◽

Structural Response ◽

Wave Theory ◽

Equation Of Motion ◽

Analytical Investigation ◽

Response Analysis ◽

Wave Forces ◽

Tension Leg Platform ◽

Heave Motion ◽

Diffraction Effects

Having deep view in structural response of tension leg platform is important issue not only for response analysis but also for engineering design. Coupling between surge and heave motions of tension leg platform is such a problem. Here, tension leg platform motions are considered only in surge and heave degrees of freedom without pitch effect. The coupled term of heave is a nonlinear differential equation. Because the focus of this article is on this term, therefore, Duffing equation of motion in the surge direction is linearized. The wave forces are calculated using Airy’s wave theory and Morison’s equation, ignoring the diffraction effects. Current force also can be very important in dynamic analysis of tension leg platform. Because it affects the term of heave that is coupled with surge. It is shown that the effect of surge motion coupling on heave motion is very important in large displacement of surge motion in many sea states. The main result is that the coupling effects appeared in some frequencies such as heave and surge frequency, twice the frequency of wave, twice the natural surge frequency, and summation and difference of frequency of wave and surge frequency.

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Assessment of Structural Performance and Integrity for Vibration-based Energy Harvester in Frequency Domain

Electronics ◽

10.3390/electronics9020357 ◽

2020 ◽

Vol 9 (2) ◽

pp. 357

Author(s):

Ji-Won Jin ◽

Ki-Weon Kang

Keyword(s):

Frequency Domain ◽

Natural Frequency ◽

Production Efficiency ◽

Performance Test ◽

Energy Harvester ◽

Structural Integrity ◽

Structural Response ◽

Structural Performance ◽

Railway Vehicle ◽

Response Analysis

A vibration-based energy harvester (VEH) utilizes vibrations originated from various structures and specifically maximizes the displacement of its moving parts, using the resonance between the frequency of external vibration loads from the structure and the natural frequency of VEH to improve power production efficiency. This study presents the procedure to evaluate the structural performance and structural integrity of VEH utilized in a railway vehicle under frequency domain. First of all, a structural performance test was performed to identify the natural frequency and assess the structural response in frequency domain. Then, the static structural analysis was carried out using FE analysis to investigate the failure critical locations (FCLs) and effect of resonance. Finally, we conducted a frequency response analysis to identify the structural response and investigate the structural integrity in frequency domain. Based on these results, the authors assessed the structural performance and integrity of VEHs in two versions.

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Numerical Simulation on Fatigue Life Assessment of Free Span for Submarine Pipeline

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.750.153 ◽

2015 ◽

Vol 750 ◽

pp. 153-159

Author(s):

Jie Dong ◽

Xue Dong Chen ◽

Bing Wang ◽

Wei He Guan ◽

Tie Cheng Yang ◽

...

Keyword(s):

Numerical Simulation ◽

Fatigue Life ◽

Oil And Gas ◽

Structural Response ◽

Simulation Method ◽

Life Assessment ◽

Response Analysis ◽

Submarine Pipeline ◽

Fatigue Life Assessment ◽

Harmonic Response Analysis

The upper and lower courses of sea oil and gas exploitationare connected by submarine pipeline which is called life line project. Free span often occurs because of the unevenness and scour of seabed, and fatigue is one of the main failure modes.In this paper, with the finite element numerical simulation method, based on the harmonic response analysis, the research on the structural response of free span under the vibration induced by vortex was investigated, and the effect of the factors such as flow velocity, length of free span. According to the analysis results,the fatigue life of free span was evaluated.

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Explosion, Fire and Structural Response Analysis

10.2118/61502-ms ◽

2000 ◽

Author(s):

R. Johnsen ◽

S.R. Ryum

Keyword(s):

Structural Response ◽

Response Analysis

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New Seismic Design Specifications of Highway Bridges in Japan

Earthquake Spectra ◽

10.1193/1.1585777 ◽

1994 ◽

Vol 10 (2) ◽

pp. 333-356 ◽

Cited By ~ 5

Author(s):

Kazuhiko Kawashima ◽

Kinji Hasegawa

Keyword(s):

Reinforced Concrete ◽

Dynamic Response ◽

Seismic Design ◽

Structural Response ◽

Highway Bridges ◽

Lateral Force ◽

Inertia Force ◽

Response Analysis ◽

Design Specifications ◽

Recent Earthquakes

This paper presents the new seismic design specifications for highway bridges issued by the Ministry of Construction in February 1990. Revisions of the previous specifications were based on the damage characteristics of highway bridges that were developed after the recent earthquakes. The primary revised items include the seismic lateral force, evaluation of inertia force for design of substructures considering structural response, checking the bearing capacity of reinforced concrete piers for lateral load, and dynamic response analysis. Emphasis is placed on the background of the revisions introduced in the new seismic design specifications.

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Effects of Empirical Orthogonal Functions in Simplification of Structural Response of a Deep-Water Offshore System Under Current Profile Loading

Volume 6B: Ocean Engineering ◽

10.1115/omae2020-18202 ◽

2020 ◽

Author(s):

Michael Binsar Lubis ◽

Mehrdad Kimiaei ◽

Hongwei An ◽

Reza Azarhoush

Keyword(s):

Deep Water ◽

Structural Response ◽

Time History ◽

Empirical Orthogonal Functions ◽

Response Analysis ◽

Good Representation ◽

Current Profile ◽

Orthogonal Functions ◽

Recent Developments ◽

Guidelines And Standards

Abstract Typical recommended current profiles for marine operations can be found in offshore engineering guidelines and standards. However, for some offshore components (e.g. risers, umbilicals, risers) typical simplified current profiles can easily lead to unrealistic and conservative results. Due to recent developments in current measuring technology, current speed for deep water location can be easily acquired. However, the current speeds are usually recorded for long periods and in many measurement points along the water column. Hence, finding the extreme current profile based on the recorded time-history data is not an easy task since it needs excessive computational efforts. To determine the overall response of an offshore system, various methods have been developed to minimize the required computational efforts in working with big number of irregular current profiles. Mode-based analysis using empirical orthogonal functions is one of these methods. Total number of the utilized modes plays an important role in the numerical complexity of the problem as well as the accuracy of the results. In this study, for a given deep water location, the effects of the reduced number of modes are investigated through response analysis of a simple vertical fixed slender structure under thousands of current profiles. It is found that the reduced-mode profile can produce a good representation of the measured current profile, however it tends to underestimate the structural response.

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