Inelastic Limit States Design Part II: Three‐Dimensional Frame Study

1992 ◽  
Vol 118 (9) ◽  
pp. 2550-2568 ◽  
Author(s):  
Ronald D. Ziemian ◽  
William McGuire ◽  
Gregory G. Dierlein
Keyword(s):  
Three Dimensional ◽  
Limit States

scholarly journals Fragility Assessment of a Container Crane under Seismic Excitation Considering Uplift and Derailment Behavior

2019 ◽  
Vol 9 (21) ◽  
pp. 4660
Author(s):  
Quang Huy Tran ◽  
Jungwon Huh ◽  
Nhu Son Doan ◽  
Van Ha Mac ◽  
Jin-Hee Ahn
Keyword(s):  
Structural Damage ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Seismic Excitation ◽  
Damage State ◽  
Limit States ◽  
Container Crane

While the container crane is an important part of daily port operations, it has received little attention in comparison with other infrastructures such as buildings and bridges. Crane collapses owing to earthquakes affect the operation of the port and indirectly impact the economy. This study proposes fragility analyses for various damage levels of a container crane, thus enabling the port owner and partners to better understand the seismic vulnerability presented by container cranes. A large number of nonlinear time-history analyses were applied for a three-dimensional (3D) finite element model to quantify the vulnerability of a Korean case-study container crane considering the uplift and derailment behavior. The uncertainty of the demand and capacity of the crane structures were also considered through random variables, i.e., the elastic modulus of members, ground motion profile, and intensity. The results analyzed in the case of the Korean container crane indicated the probability of exceeding the first uplift with or without derailment before the crane reached the structure’s limit states. This implies that under low seismic excitation, the crane may be derailed without any structural damage. However, when the crane reaches the minor damage state, this condition is always coupled with a certain probability of uplift with or without derailment. Furthermore, this study proposes fragility curves developed for different structural periods to enable port stakeholders to assess the risk of their container crane.

scholarly journals Significance of geotechnical loads on local buckling response of buried pipelines with respect to conventional practice

2013 ◽  
Vol 50 (1) ◽  
pp. 68-80 ◽  
Author(s):  
Hiva Mahdavi ◽  
Shawn Kenny ◽  
Ryan Phillips ◽  
Radu Popescu
Keyword(s):  
Load Transfer ◽  
Mechanical Performance ◽  
Three Dimensional ◽  
Local Buckling ◽  
Element Model ◽  
Combined Loading ◽  
Buried Pipelines ◽  
Buried Pipe ◽  
Limit States ◽  
New Criterion

Long-term large deformation geohazards can impose excessive deformation on a buried pipeline. The ground displacement field may initiate pipeline deformation mechanisms that exceed design acceptance criteria with respect to serviceability requirements or ultimate limit states. The conventional engineering approach to define the mechanical performance of pipelines has been based on combined loading events for in-air conditions. This methodology may be conservative, as it ignores the soil effect that imposes geotechnical loads, and also provides restraint, on buried pipelines. The importance of pipeline–soil interaction and load-transfer mechanisms that may affect local buckling of buried pipelines is not well understood. A three-dimensional continuum finite element model, simulating the local buckling response of a buried pipe, using the software package ABAQUS/Standard was developed and calibrated. A comprehensive parametric study was previously conducted to investigate the effect of several parameters on local buckling response of pipelines buried in firm clay. A new strain criterion for local buckling of buried pipelines in firm clay through response surface methodology was developed. In this paper, the new criterion is compared with several existing in-air criteria to study the effect of soil restraint on the local buckling response of buried pipelines. The criterion developed in this study predicts greater characteristic critical strain capacity than in-air based criteria that highlights the influence of soil restraint.

scholarly journals Fragility Assessment of Container Crane under Seismic Excitation Considering Uplift and Derailment Behavior

2019 ◽  
Author(s):  
Quang Huy Tran ◽  
Jungwon Huh ◽  
Nhu Son Doan ◽  
Van Ha Mac ◽  
Jin-Hee Ahn
Keyword(s):  
Structural Damage ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Seismic Excitation ◽  
Damage State ◽  
Limit States ◽  
Container Crane

While the container crane is an important part of daily port operations, it has received little attention compared with other infrastructures, such as buildings and bridges. Crane collapse due to earthquake affects the operation of the port, and indirectly impacts the economy. This study proposes fragility analyses for various damage levels of the container crane that allow the port owner and partners to better understand the seismic vulnerability presented by container cranes. A large quantity of nonlinear time history analyses was applied for a three-dimensional (3D) finite element model to quantify the vulnerability of the container crane in considering the uplift and derailment behavior. The uncertainty of demand and capacity of the crane structures were also considered through random variables, i.e. elastic modulus of members, ground motion profile, and intensity. The results analyzed in the case of a Korean container crane showed that the probability of exceeding the first uplift with or without derailment is shown before the crane reaches the structure’s limit states. This means that under low seismic excitation, the crane might be derailed without any structural damage. But when the crane reaches the minor damage state, it is always coupled with a certain probability of uplift with or without derailment. This study also proposes the fragility curves developed for different structural periods to enable port stakeholders to assess the risk of their container crane.

scholarly journals Recent Industrial Developments of Marine Composites Limit States and Design Approaches on Strength

2020 ◽  
Author(s):  
Beatrice Barsotti ◽  
Marco Gaiotti ◽  
Cesare Mario Rizzo
Keyword(s):  
Failure Modes ◽  
Three Dimensional ◽  
Offshore Structures ◽  
Structural Domain ◽  
Limit States ◽  
Ship Hulls ◽  
Starting Point ◽  
Current Design ◽  
The One ◽  
Marine Composite

Abstract To further exploit the potential of marine composites applications in building ship hulls, offshore structures, and marine equipment and components, design approaches should be improved, facing the challenge of a more comprehensive and explicit assessment of appropriately defined limit states. The structure ultimate/limit conditions shall be verified in principle within the whole structural domain and throughout the ship service life. What above calls for extended and reliable materials characterization on the one hand and for accurate and wide-ranging procedures in structural analyses. This paper presents an overview of recent industrial developments of marine composites limit states assessments and design approaches, as available in open literature, focusing on pleasure crafts and yachts as well as navy ships and thus showing a starting point to fill the gap in this respect. After a general introduction about composites characterization techniques, current design practice and rule requirements are briefly summarized. Both inter-ply and intra-ply failure modes and corresponding limit states are then presented along with recently proposed assessment approaches. Three-dimensional aspects in failure modes and manufacturing methods have been identified as the main factors influencing marine composite robustness. Literature review highlighted also fire resistance and hybrid joining techniques as significant issues in the use of marine composites.

New proposed drift limit states for box-type structural systems considering local and global damage indices

2019 ◽  
Vol 22 (15) ◽  
pp. 3352-3366 ◽  
Author(s):  
Vahid Mohsenian ◽  
Alireza Mortezaei
Keyword(s):  
Damage Index ◽  
Three Dimensional ◽  
Local Damage ◽  
Structural System ◽  
Limit States ◽  
Maximum Displacement ◽  
Damage Indices ◽  
Expected Performance ◽  
Immediate Occupancy ◽  
Drift Limit

The maximum displacement responses under the seismic motions are usually considered as an indicator for damage evaluation. It is obvious that appropriate selection of drifts corresponding to various damage levels plays an important role in safety and economy of a design project. Despite the extensive use of the box-type structural system in mass construction and housing industry, there is no special design requirement for this structural system. Due to three-dimensional behavior and interaction of intersecting walls and slabs, it is expected that this system presents different seismic performance in comparison to the conventional shear wall buildings. This study evaluates the overall and story failure mechanism as well as global and local damage indices in this structural system. Maximum allowable drift ratios of 0.45%, 0.65%, and 0.8% are suggested for the immediate occupancy, life safety, and collapse prevention levels, respectively. Moreover, a damage index based on the maximum relative inter-story drifts is proposed to assess the failure in the height domain. According to the assessments, the story and global failure occurring due to considerable damages in main load bearing elements reveals high importance of local damage indices in box-type structural system. Based on the results, it is concluded that the proposed maximum values for drifts in different standards and codes are not reliable. Considering the shear-control behavior and depending on the expected performance levels, the proposed local damage indices are considered as accurate control indicators for box-type structural system.

scholarly journals Mechanism and Integrated Control of “Rib Spalling: Roof Collapse—Support Instability” Hazard Chains in Steeply Dipping Soft Coal Seams

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Shuai Liu ◽  
Ke Yang ◽  
Chunan Tang
Keyword(s):  
Underground Mining ◽  
Integrated Control ◽  
Three Dimensional ◽  
Friction Angle ◽  
Coal Seams ◽  
Limit States ◽  
Roof Collapse ◽  
Soft Coal ◽  
Wall Element ◽  
Coal Wall

The hazard chain of rib spalling, roof collapse, and support instability occurring in steeply dipping coal seams (SDCSs) significantly threatens the safety and productivity of underground mining. A three-dimensional coal wall model was established considering the damage to the coal wall from the abutment pressure based on the new concept of the main control weak surface (MCWS) defined by the authors. Then, a support mechanical model under the conditions of a dynamic load induced by a sliding roof was constructed. Integrated control measurements based on the models above were developed and taken for the dangerous area of hazard chains in working faces. The results indicated that the dimensions of rib spalling were dominated by the shape, dimensions, and friction angle of the coal wall element. In detail, the order of the importance of the element failure factors, based on their sensitivities, was the roof load (6.33), the dip of the panel (−5.03), the friction angle of the coal (−3.24), the cohesion of the coal (−3.02), and the sidewall protecting force (−0.087). Additionally, the order of importance of the frictional sliding factors of the slip body was the MCWS cohesion (−0.293), roof load (0.213), and MCWS friction angle (−0.079). Equations for the threshold forces between supports under the support dumping and sliding limit states were obtained; the knowledge of these forces ensured support stability under a sliding roof. The support work resistance varied synchronously in different parts of the working face and remained within 2200–4000 kN, indicating that the proposed models and control measurements considered instrumental in hazard chain control in SDCSs were reliable.

Buried Corrugated Thermoplastic Pipe: Simulation and Design

2003 ◽  
Vol 1849 (1) ◽  
pp. 135-143 ◽  
Author(s):  
B. W. Schafer ◽  
T. J. McGrath
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Design Method ◽  
Three Dimensional ◽  
Local Buckling ◽  
Element Model ◽  
Computational Method ◽  
Limit States ◽  
Strain Capacity ◽  
Negative Bending

The objective of this study was to demonstrate a computational method for assessing the allowable depth of fill over a buried thermoplastic profile wall (corrugated) plastic pipe and to compare the results with those of the recently adopted AASHTO design method. The computational method is demonstrated for a 1,500-mm (60-in.) diameter high-density polyethylene profile wall pipe but is applicable to all profile wall thermoplastic pipe that exhibits local buckling limit states. The computational model compares strain demands predicted from a two-dimensional plane strain finite element model of buried pipe in the embankment condition with strain capacity predicted from a three-dimensional finite element model of a pipe–soil segment undergoing thrust or positive and negative bending, or both. The strain demands indicate the dominance of thrust strains as opposed to bending strains in the overall behavior, particularly for intermediate to larger fill depths. In the examined profile the ultimate strain capacity is limited by local buckling for thrust strains and positive bending (crest in compression) and inward radial movement of the crest for negative bending (liner in compression). Predictions for depth of fill by the new AASHTO design method for thermoplastic pipe and the computational method agree within 10% of one another when uniform soil distribution is considered and within 20% of one another when a soft haunch and other soft soils are considered in the pipe–soil envelope.

The orbit of Pluto over a long interval of time

1966 ◽  
Vol 25 ◽  
pp. 227-229 ◽  
Author(s):  
D. Brouwer
Keyword(s):  
Periodic Orbit ◽  
Numerical Integration ◽  
Restricted Problem ◽  
Three Dimensional ◽  
The Third ◽  
Circular Restricted Problem ◽  
Resonance Relation

The paper presents a summary of the results obtained by C. J. Cohen and E. C. Hubbard, who established by numerical integration that a resonance relation exists between the orbits of Neptune and Pluto. The problem may be explored further by approximating the motion of Pluto by that of a particle with negligible mass in the three-dimensional (circular) restricted problem. The mass of Pluto and the eccentricity of Neptune's orbit are ignored in this approximation. Significant features of the problem appear to be the presence of two critical arguments and the possibility that the orbit may be related to a periodic orbit of the third kind.

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