scholarly journals Characterising Penetrometer Tip Contact during Concrete Condition Assessment

2021 ◽  
Author(s):  
Richard Hall ◽  
Alex Stumpf ◽  
Avinash Baji ◽  
Robert Ross ◽  
Dean Barnett
Keyword(s):  
Concrete Surface ◽  
Condition Assessment ◽  
Parametric Models ◽  
Element Analysis ◽  
Concrete Corrosion ◽  
Concrete Condition ◽  
Concrete Pipe ◽  
Soft Surface ◽  
Semi Solid ◽  
Better Than

Concrete condition assessing penetrometers need to be able to distinguish between making contact with a hard (concrete) surface as opposed to a semi-solid (corroded concrete) surface. If a hard surface is mistaken for a soft surface, concrete corrosion may be over-estimated, with the potential for triggering unnecessary remediation works. Unfortunately, the variably-angled surface of a concrete pipe can cause the tip of a force-sensing tactile penetrometer to slip and thus to make this mistake. We investigated whether different shaped tips of a cylindrical penetrometer were better than others at maintaining contact with concrete and not slipping. We designed a range of simple symmetric tip shapes, controlled by a single superellipse parameter. We performed a finite element analysis of these parametric models in SolidWorks before machining in stainless steel. We tested our penetrometer tips on a concrete paver cut to four angles at 20∘ increments. The results indicate that penetrometers with a squircle-shaped steel tip (a=b=1,n=4) have the least slip, in the context of concrete condition assessment.

Analysis and Comparison of Seal Ability of Premium Tubing Connections under Axial Alternating Load

2013 ◽  
Vol 423-426 ◽  
pp. 2035-2039
Author(s):  
Long Cang Huang ◽  
Yin Ping Cao ◽  
Yang Yu ◽  
Yi Hua Dou
Keyword(s):  
Contact Pressure ◽  
Oil And Gas ◽  
Element Analysis ◽  
Gas Well ◽  
Cycle Number ◽  
Compression Load ◽  
Well Production ◽  
Maximum Contact ◽  
Contact Pressures ◽  
Better Than

In the process of oil and gas well production, tubing connection stand the axial alternating load during open well, shut well and fluid flow. In order to know premium connection seal ability under the loading, two types of P110 88.9mmx6.45mm premium tubing connections which called A connection and B connection are performed with finite element analysis, in which contact pressures and their the regularities distribution on sealing surface are analyzed. The results show that with the increasing of cycle number, the maximum contact pressures on sealing surface of both A connection and B connection are decreased. The decreasing of the maximum contact pressures on B connection is greater than those on A connection. With the increasing of cycle number of axial alternating compression load, the maximum contact pressure on sealing surface of A connection is decreased, and the maximum contact pressure on sealing surface of B connection remains constant. Compared the result, it shows that the seal ability of A connection is better than B connection under axial alternating tension load, while the seal ability of B connection is better than type A connection under axial alternating compression load.

scholarly journals Design of a Novel Six-Axis Wrist Force Sensor

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3120 ◽  
Author(s):  
Shanshan Hu ◽  
Huaiyang Wang ◽  
Yong Wang ◽  
Zhengshi Liu
Keyword(s):  
Simulation Analysis ◽  
Dynamic Performance ◽  
Force Sensor ◽  
The Novel ◽  
Element Analysis ◽  
Body Design ◽  
Design Idea ◽  
Bridge Circuits ◽  
Design Ideas ◽  
Better Than

A novel elastic body design idea of six-axis wrist force sensor with a floating beam was raised based on the analysis of the robot six-axis wrist force sensor with a floating beam. The design ideas improve the sensor’s dynamic performance significantly, while not reducing its sensitivity. First, the design ideas were described in detail, which were analyzed by mechanical modeling and were verified by finite element analysis. Second, the static simulation analysis of the novel elastomer of sensor was carried out. According to the strain distribution performance, the position of the strain gauges pasted and the connection mode of the full-bridge circuits were decided, which can achieve theoretical decoupling. Finally, the comparison between the static and dynamic performance of the novel sensor and the original sensor with floating beams was done. The results show that the static and dynamic performance of the novel six-axis wrist sensor are all better than the original sensor.

Using the Asphalt Pavement Layer Condition Assessment Program: Case Studies

2003 ◽  
Vol 1860 (1) ◽  
pp. 66-75 ◽  
Author(s):  
Bing Xu ◽  
S. Ranji Ranjithan ◽  
Y. Richard Kim
Keyword(s):  
Case Studies ◽  
Asphalt Pavement ◽  
Compressive Strain ◽  
Dynamic Effect ◽  
Field Measurements ◽  
Condition Assessment ◽  
Base Layer ◽  
Element Analysis ◽  
Condition Indicators ◽  
Assessment Program

The Asphalt Pavement Layer Condition Assessment Program (APLCAP) is developed in this research to help highway agencies assess layer conditions of asphalt pavements. APLCAP implements a new integrated procedure for condition assessment from falling-weight deflectometer (FWD) deflections. The main components of this procedure include screening of FWD raw deflections, predictions of condition indicators from FWD measurements, structural adjustments for the predicted condition indicators, and layer condition evaluation based on the adjusted condition indicators. This procedure was developed on the basis of dynamic nonlinear finite element analysis and calibrated using field measurements. The three case studies presented show that the APLCAP algorithms can predict the asphalt concrete modulus, pavement critical strains, and strengths of the base and subgrade quite well, but not the compressive strain in the aggregate base layer. Although the APLCAP procedure includes the complicated dynamic effect of FWD loading and nonlinear behavior of unbound materials, the time to obtain results from this procedure is insignificant and therefore suitable for real-time evaluation of pavement conditions.

Mechanical Design of Antichiral-Reentrant Hybrid Intravascular Stent

2018 ◽  
Vol 10 (10) ◽  
pp. 1850105 ◽  
Author(s):  
Xiao Li Ruan ◽  
Jie Jie Li ◽  
Xiao Ke Song ◽  
Hong Jian Zhou ◽  
Wei Xing Yuan ◽  
...  
Keyword(s):  
Large Scale ◽  
Mechanical Design ◽  
Experimental Tests ◽  
Building Blocks ◽  
Industrial Applications ◽  
Mechanical Effect ◽  
Parametric Models ◽  
Element Analysis ◽  
Specific Strength ◽  
Intravascular Stents

Chiral and reentrant metastructures with auxetic deformation abilities can serve as the building blocks in many industrial applications because of their light weight, high specific strength, energy absorption properties. In this paper, we report an innovative tubular-like structure by a combined mechanical effect of antichiral and reentrant. 2D antichiral-reentrant hybrid structures consisting of circular nodes and tangentially-connected ligaments are predesigned and fabricated using laser cutting technology with high-resolution. The elastic properties and auxeticity of the plane structure are analyzed and compared based on finite element analysis (FEA) and experimental results. For the first time, the antichiral-reentrant hybrid intravascular stents with the auxetic feature are proposed and parametric models are devised with good geometrical structure demonstrated. A series of large-scale stents are manufactured with stereolithography apparatus (SLA) additive manufacturing technique, and their mechanical behaviors are investigated in both experimental tests and FEA. As the selected antichiral-reentrant hybrid stents with tailored expansion ability are subjected to radial loading by the dilation of the balloon, stents undergo identifiable deformation mechanism due to the beam-like ligaments and circular node elements in the varied geometrical design, resulting in the distinct stress outcomes in plaque. It is also demonstrated that the antichiral-reentrant hybrid stents with tunable auxeticity possess robust mechanical properties through implantation inside the obstructed lesion.

Correlation between Microstructure and Properties of Semi-Solid Products

2019 ◽  
Vol 285 ◽  
pp. 12-23 ◽  
Author(s):  
Annalisa Pola
Keyword(s):  
Mechanical Properties ◽  
Fatigue Wear ◽  
Microstructure And Properties ◽  
Tensile Fatigue ◽  
Wear And Corrosion ◽  
Semi Solid ◽  
Wear And Corrosion Resistance ◽  
Permanent Mold Castings ◽  
The Relationship ◽  
Better Than

Since the very first production trials, it was evident that semi-solid components exhibit excellent mechanical properties, comparable to those of forged material and, in any case, better than permanent mold castings. Over the years, these findings have been confirmed by many authors. Most of the papers available in scientific literature deals with the demonstration of this improvement, especially in order to show the reliability of new and alternative production routes. On the contrary, only some studies focus their attention on the relationship between enhanced mechanical properties and the microstructure. However, it is demonstrated that the increased performance of semi-solid components is not only due to the absence of porosity, but there is a clear relationship between microstructure and properties. This paper reports about the state of knowledge in this subject, in particular for what concerns tensile, fatigue, wear and corrosion resistance.

scholarly journals Static Experiment and Finite Element Analysis of a Multitower Cable-Stayed Bridge with a New Stiffening System

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaowei Wang ◽  
Yingmin Li ◽  
Weiju Song ◽  
Jun Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Force ◽  
Element Analysis ◽  
Cable Stayed Bridge ◽  
Practical Engineering ◽  
Static Experiment ◽  
Stiffening Effect ◽  
Better Than ◽  
Cable Stayed Bridges

Based on the stiffness limitations of the midtower in multitower cable-stayed bridges, a new stiffening system (tie-down cables) is proposed in this paper. The sag effects and wind-induced responses can be reduced with the proposed system because tie-down cables are short and aesthetic compared with traditional stiffening cables. The results show that the stiffening effect of tie-down cables is better than that of traditional stiffening cables in controlling the displacement and internal force of the bridge based on a static experiment and finite element analysis. Therefore, the proposed system can greatly improve the overall stiffness of a bridge, and its stiffening effect is better than that of traditional stiffening cables in controlling the displacement and internal force. The results provide a reference for the application of such systems in practical engineering.

A Scanning X-Ray Fluorescence Microprobe with Synchrotron Radiation

1987 ◽  
Vol 31 ◽  
pp. 495-502 ◽  
Author(s):  
Y. Gohshj ◽  
S. Aoki ◽  
A. Iida ◽  
S. Hayakawa ◽  
H. Yamaji ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Relative Concentration ◽  
Trace Element Analysis ◽  
Design Parameters ◽  
Absolute Amount ◽  
Beam Size ◽  
Element Analysis ◽  
X Ray ◽  
Better Than

SummaryA scantling X-ray fluorescence(XRF) microprobe using WoIter type 1 optics was developed, and micro and trace element analysis was carried out using synchrotron radiation up to 10 keV as an excitation source. The design parameters of the optical system and the performance of the system, such as the beam size and the intensity, are described. The MDL obtained for Mn was 6 ppm in relative concentration and about 0.1 pg in absolute amount. The estimated spatial resolution was better than 10 um.

Friction and Texture Retention of Concrete Pavements

2020 ◽  
Vol 2674 (6) ◽  
pp. 457-465
Author(s):  
Satyavati Komaragiri ◽  
Armen Amirkhanian ◽  
Amit Bhasin
Keyword(s):  
Coarse Aggregate ◽  
Concrete Surface ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Department Of Transportation ◽  
Polishing Process ◽  
Friction Tester ◽  
Circular Track ◽  
Grinding Operations ◽  
Better Than

In the late 1980s and early 1990s, the Alabama Department of Transportation (ALDOT), U.S., noticed a decline in skid trailer numbers on concrete pavements shortly after grinding operations. The engineers at the time suspected that the coarse aggregate caused the decline in these numbers and the resulting conclusion led to a ban of carbonate aggregates in mainline concrete pavement in Alabama that is still in place. This detailed laboratory study re-examines the fundamental friction issues that led to this policy. A total of 48 aggregate, grinding, and grooving combinations were tested as part of this study. Three aggregate sources were examined: a siliceous source, a “hard” limestone source, and a “soft” limestone source. Two blade spacings were examined for grinding operations: 52 blades/ft and 60 blades/ft. Some ground specimens were also grooved. Finally, a set of specimens had the Next Generation Concrete Surface (NGCS) applied to them. The specimens were polished with the National Center for Asphalt Technology (NCAT) three-wheel polishing device (TWPD). The dynamic friction tester was used to evaluate friction values at various points through the polishing process. After the polishing, the macrotexture was characterized using the circular track meter. Across the board, the highest performing texture was that with no grooves and 52 blades/ft. Very generally, the loss of friction decreased with increasing siliceous content. However, some of the trends were extremely minor and, in a few cases, siliceous aggregates caused higher friction loss. There were numerous instances when blended carbonate/siliceous concrete pavement surfaces performed better than sole siliceous concrete pavement surfaces.

scholarly journals Experimental Study on Hysteretic Behavior of the Overlapped K-Joints with Concrete Filled in Chord

2019 ◽  
Vol 9 (7) ◽  
pp. 1456 ◽  
Author(s):  
Wenwei Yang ◽  
Ruhao Yan ◽  
Yaqi Suo ◽  
Guoqing Zhang ◽  
Bo Huang
Keyword(s):  
Plastic Deformation ◽  
Energy Dissipation ◽  
Cyclic Loading ◽  
Bearing Capacity ◽  
Failure Modes ◽  
The United States ◽  
Hysteretic Behavior ◽  
Tensile Failure ◽  
Element Analysis ◽  
Better Than

Due to the insufficient radial stiffness of the steel tube, the cracking of the weld and the plastic deformation of the string often occur under the cyclic loading of the hollow section pipe joint. In order to avoid such a failure, the overlapped K-joints were strengthened by pouring different concrete into the chords. Furthermore, to explore the detailed effect of filling different concrete in a chord on the hysteretic behavior of the overlapped K-joints, six full-scale specimens were fabricated by two forms, which included the circular chord and braces, the square chord and circular braces, and the low cyclic loading tests, which were carried out. The failure modes, hysteretic curves and skeleton curves of the joints were obtained, and the bearing capacity, ductility and energy dissipation of the joints were evaluated quantitatively. The results showed that plastic failure occurs on the surface of the chord of the joints without filling concrete, while the failure mode of the joints filled with concrete in the chords was the tensile failure of the chords at the weld of the brace toe, and the compressive braces had a certain buckling deformation; The strengthening measures of concrete filled with chord can effectively improve the mechanical properties of the K-joints, the delay of the plastic deformation of the chord, and improve the bearing capacity of the K-joints. Contrarily, the ductility coefficient and the energy dissipation ratio of K-joints decreased with the concrete filled in the chord. The hysteretic behavior of the K-joints with a circular chord and brace was slightly better than that of the K-joints with a square chord and circular brace, and the hysteretic behavior of the K-joints strengthened with fly ash concrete, which was better than that of the K-joints strengthened with ordinary concrete. The results of ANSYS (a large general finite element analysis software developed by ANSYS Company in the United States) analysis agreed well with the experimental results.

Analysis the Influence of Non-Prestressed Reinforcement for Horizontal Bearing Capacity of PHC Pipe Pile

2014 ◽  
Vol 919-921 ◽  
pp. 649-653
Author(s):  
Pei Sheng Xi ◽  
Xiao Kai Sun
Keyword(s):  
Bearing Capacity ◽  
Poor Performance ◽  
Analysis Software ◽  
Element Analysis ◽  
Prestressing Steel ◽  
Concrete Piles ◽  
The Poor ◽  
Concrete Pile ◽  
Prestressed Reinforcement ◽  
Better Than

We analyze the configuration of the non-pretressed reinforcement impact on the level of bearing capacity of PHC piles to effectively solve the poor performance of the general bending of pretressed concrete pile,using ANSYS finite element analysis software,through configurating the pretressed concrete pile with appropriate amount of ordinary non-presressed reinforcement.The results of numerical calculation show that the performance of PHC pile bending has been greatly improved and the deflection and bending when cracking were significantly better than ordinary PHC pile with the confiuration of non-prestressed reinforcement. We also analyze the effect of non-prestressed reinforcement and prestressing steel when the concrete piles cracking,datd shows that prestressing steel reached stress yielding firstly.The results provide a theoretical basis of the application of precast piles in the foudation ditch support project.

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