Assessment of Existing Bridge’s Beam Bending Stiffness Using Crack Characteristics

By means of inertia-moment method, formulae are derived for calculating flexural rigidity of RC beams under different loading stage, which can be used for calculating initial rigidity and rigidity in service stage. Involving less parameters, it’s convenient to use the formulae. As for four examples, calculations are carried out by both code method and formulations given in this paper, and satisfied results are shown. Further more, based on finite rib method, nonlinear-all-rang analysis is done for M-B of beam sections.

Download Full-text

Modelling Changes to Submarine Pipeline Embedment and Stability due to Pipeline Scour

Volume 5: Pipelines, Risers, and Subsea Systems ◽

10.1115/omae2018-77985 ◽

2018 ◽

Author(s):

Scott Draper ◽

Terry Griffiths ◽

Liang Cheng ◽

David White ◽

Hongwei An

Keyword(s):

Bending Stiffness ◽

Probabilistic Framework ◽

Submarine Pipeline ◽

Length Scales ◽

Sediment Mobility ◽

Beam Bending ◽

Predictive Formulas ◽

Seabed Roughness

In this paper a beam bending model is combined with existing predictive formulas for pipeline scour to study changes to pipeline stability during scour and lowering. The model is introduced and demonstrated for a range of simplified conditions, including scour-induced lowering of a pipeline resulting from multiple uniformly spaced scour initiation points. The model is then used with a synthetic seabed generated with a variety of length scales. In this simulation the pipeline is ‘laid’ onto the seabed, leading to the formation of ‘natural’ initiation points for scour. The distribution and spacing of the initiation points (which are a function of the pipeline bending stiffness, tension and seabed roughness) lead to different rates of pipeline lowering and stability. The resulting model may be used within a probabilistic framework to estimate changes to pipeline stability resulting from sediment mobility and scour.

Download Full-text

Round-robin analysis of the RILEM TC 162-TDF beam-bending test: Part 3 - Fibre distribution

Materials and Structures ◽

10.1617/13955 ◽

2003 ◽

Vol 36 (263) ◽

pp. 631-635 ◽

Cited By ~ 3

Author(s):

Keyword(s):

Round Robin ◽

Bending Test ◽

Fibre Distribution ◽

Test Part ◽

Beam Bending

Download Full-text

CALCULATION-EXPERIMENTAL METHOD FOR DEFINITION OF LOWEST FREQUENCY IN BENDING VIBRATIONS OF COACH CAR BODY IN VERTICAL PLANE BASED ON IDENTIFICATION OF ITS BENDING STIFFNESS

Bulletin of Bryansk state technical university ◽

10.30987/1999-8775-2020-9-34-45 ◽

2020 ◽

Vol 2020 (9) ◽

pp. 35-46

Author(s):

Aleksandr Skachkov ◽

Viktor Vasilevskiy ◽

Aleksey Yuhnevskiy

Keyword(s):

Least Squares Method ◽

Vertical Plane ◽

Bending Stiffness ◽

Dimensional Problem ◽

Euler Beam ◽

Bending Vibrations ◽

Car Body ◽

Variable Function ◽

Experimental Values ◽

Definition Of

The consideration of existing methods for a modal analysis has shown a possibility for the lowest frequency definition of bending vibrations in a coach car body in a vertical plane based on an indirect method reduced to the assessment of the bending stiffness of the one-dimensional model as a Bernoulli-Euler beam with fragment-constant parameters. The assessment mentioned can be obtained by means of the comparison of model deflections (rated) and a prototype (measured experimentally upon a natural body) with the use of the least-squares method that results in the necessity of the solution of the multi-dimensional problem with the reverse coefficient. The introduction of the hypothesis on ratability of real bending stiffness of the prototype and easily calculated geometrical stiffness of a model reduces a multi-dimensional problem incorrect according to Adamar to the simplest search of the extremum of one variable function. The procedure offered for the indirect assessment of bending stiffness was checked through the solution of model problems. The values obtained are offered to use for the assessment of the lowest frequency of bending vibrations with the aid of Ritz and Grammel methods. In case of rigid poles it results in formulae for frequencies into which there are included directly the experimental values of deflections.

Download Full-text

Paper and board � Determination of bending stiffness � General principles for two-point, three-point and fourpoint methods

10.3403/30205405u ◽

2019 ◽

Keyword(s):

Bending Stiffness

Download Full-text

A Simple Closed-Form Solution of Bending Stiffness for Laminated Composite Tubes

Journal of Reinforced Plastics and Composites ◽

10.1106/y1h1-25tk-1m0j-wj2x ◽

2000 ◽

Vol 19 (4) ◽

pp. 278-291 ◽

Cited By ~ 4

Author(s):

WEN S. CHAN ◽

KAZIM C. DEMIRHAN

Keyword(s):

Closed Form ◽

Closed Form Solution ◽

Laminated Composite ◽

Bending Stiffness ◽

Form Solution ◽

Composite Tubes

Download Full-text

Beam Theory of Thermal–Electro-Mechanical Coupling for Single-Wall Carbon Nanotubes

Nanomaterials ◽

10.3390/nano11040923 ◽

2021 ◽

Vol 11 (4) ◽

pp. 923

Author(s):

Kun Huang ◽

Ji Yao

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Beam Theory ◽

Bending Stiffness ◽

Single Wall Carbon Nanotubes ◽

Beam Model ◽

Euler Beam ◽

New Model ◽

Mechanical Coupling ◽

Electrostatic Fields

The potential application field of single-walled carbon nanotubes (SWCNTs) is immense, due to their remarkable mechanical and electrical properties. However, their mechanical properties under combined physical fields have not attracted researchers’ attention. For the first time, the present paper proposes beam theory to model SWCNTs’ mechanical properties under combined temperature and electrostatic fields. Unlike the classical Bernoulli–Euler beam model, this new model has independent extensional stiffness and bending stiffness. Static bending, buckling, and nonlinear vibrations are investigated through the classical beam model and the new model. The results show that the classical beam model significantly underestimates the influence of temperature and electrostatic fields on the mechanical properties of SWCNTs because the model overestimates the bending stiffness. The results also suggest that it may be necessary to re-examine the accuracy of the classical beam model of SWCNTs.

Download Full-text

Rotary steerable systems: mathematical modeling and their case study

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01182-6 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2743-2761

Author(s):

Caetano P. S. Andrade ◽

J. Luis Saavedra ◽

Andrzej Tunkiel ◽

Dan Sui

Keyword(s):

Directional Drilling ◽

Steering Control ◽

Fundamental Physics ◽

Drilling Tools ◽

Drilling Operations ◽

Beam Bending ◽

Extended Reach Drilling ◽

And Control ◽

2D And 3D

AbstractDirectional drilling is a common and essential procedure of major extended reach drilling operations. With the development of directional drilling technologies, the percentage of recoverable oil production has increased. However, its challenges, like real-time bit steering, directional drilling tools selection and control, are main barriers leading to low drilling efficiency and high nonproductive time. The fact inspires this study. Our work aims to contribute to the better understanding of directional drilling, more specifically regarding rotary steerable system (RSS) technology. For instance, finding the solutions of the technological challenges involved in RSSs, such as bit steering control, bit position calculation and bit speed estimation, is the main considerations of our study. Classical definitions from fundamental physics including Newton’s third law, beam bending analysis, bit force analysis, rate of penetration (ROP) modeling are employed to estimate bit position and then conduct RSS control to steer the bit accordingly. The results are illustrated in case study with the consideration of the 2D and 3D wellbore scenarios.

Download Full-text