Analytical Method to Estimate Railroad Spike Fastener Stress

2020 ◽  
Vol 2674 (11) ◽  
pp. 379-389 ◽  
Author(s):  
Marcus S. Dersch ◽  
Matheus Trizotto Silva ◽  
J. Riley Edwards ◽  
Arthur de O Lima ◽  
Tom Roadcap
Keyword(s):  
Analytical Method ◽  
Model Development ◽  
Element Model ◽  
Foundation Design ◽  
Deep Foundation ◽  
Cross Sectional ◽  
Field Instrumentation ◽  
Key Variables ◽  
Railroad Safety ◽  
Laterally Loaded

Previous research indicates that spike fastener fatigue failures have led to at least ten derailments since 2000. Given that railroads continue to install fastening systems that have experienced spike failures, methods to quantify the stress state of the spike must be developed. Common approaches to quantify the effect of key variables include laboratory experimentation, field instrumentation, or finite element model development. However, these approaches may be both time and cost prohibitive. An analytical method based on beam on elastic foundation mechanics, similar to the analysis of laterally loaded piles in deep foundation design, was developed to estimate the spike stresses. The outcome is a laboratory-validated analytical approach that generates estimates of spike stress. This analytical model was used to investigate key design criteria (timber modulus, spike cross-sectional area, and load applied) that could be changed to improve the resiliency of the fastening system to increase railroad safety. Another outcome of this study is the development of an instrumented spike that quantifies the spike demands when installed and loaded within a crosstie.

FAKTOR PENGETAHUAN YANG MEMPENGARUHI KETERATURAN IBU BALITA DALAM MENGUNJUNGI POSYANDU DI DESA CIPANGERAN KECAMATAN SAGULING KABUPATEN BANDUNG BARAT TAHUN 2017

2018 ◽  
Vol 5 (2) ◽  
pp. 13-20
Author(s):  
Lia Kamila ◽  
Liawati . ◽  
Suci Lailani Alipah
Keyword(s):  
Public Health ◽  
Data Collection ◽  
Sample Size ◽  
Health Center ◽  
Analytical Method ◽  
Random Sampling ◽  
Research Method ◽  
Cross Sectional ◽  
Public Health Center ◽  
Level Of Knowledge

ABSTRAK Indikator D/S di wilayah kerja Puskesmas Saguling Desa Cipangeran pada tahun 2016 menunjukkan masih rendahnya kunjungan balita dalam kegiatan posyandu dengan rata-rata hanya memcapai 41,5%, sedangkan target standar palayanan kota jumlah D/S yaitu 85%. Tujuan penelitian ini adalah untuk mengetahui keteraturan ibu dalam mengunjungi Posyandu dari faktor pengetahuan di Desa Cipangeran Kecamatan Saguling Kabupaten Bandung Barat tahun 2017. Metode penelitian ini menggunakan metode analitik dengan pendekatan cross sectional. Data yang digunakan adalah data primer. Populasi seluruh balita di wilayah kerja Puskesmas Saguling tahun 2016 sebanyak 424 ibu balita, besar sampel yang diambil 81 ibu balita, pengambilan sampel dengan menggunakan Sampel Random Sampling, pengumpulan data dengan hasil kuesioner berisi pertanyaan untuk mendapatkan data yang berkaitan dengan variabel yang diteliti. Hasil penelitian pengetahuan ibu balita didapatkan hampir setengah berada dikategori cukup yaitu 47 ibu balita (58%), namun masih ada ibu balita yang memiliki pengetahuan baik yaitu 18 ibu balita (22%), dan ibu balita yang memiliki pengetahuan kurang yaitu 16 ibu balita (20%). Kesimpulan dari penelitian didapatkan tingkat pengetahuan ibu balita yang tidak teratur dalam mengunjungi Posyandu di Desa Cipangeran Kecamatan Saguling Kabupaten Bandug Barat hampir setengah ibu balita berpengetahuan cukup. ABSTRACT The D / S indicator in the working area of ​​Saguling Public Health Center of Cipangeran Village in 2016 indicates that the low number of toddler visits in posyandu activities reaches an average of 41.5%, while the standard target for city / city is 85%. The purpose of this study is to determine the regularity of mothers in visiting Posyandu from knowledge factor in Cipangeran Village, Saguling District, West Bandung regency in 2017. This research method using analytical method with cross sectional approach. The data used is primary data.The population of all toddlers in the working area of Saguling Publich Health Center in 2016 were 424 mother, the sample size was 81 mother, using Random Sampling , data collection with questionnaires containing questions to obtain data related to the variables studied. The result of the research of the knowledge of the mother of the toddler is almost sufficient, namely 47 mothers (58%),but there are still mother who have good knowledge that is 18 mother of toddler (22%) and mother with less knowledge that is 16 mother of balita (20%). The conclusion of the research is the level of knowledge of irregular mother in visiting Posyandu in Cipangeran Village, Saguling, of West Bandung district, almost half of the toddler are knowledgeable enough.

scholarly journals Development of Simulation Based p-Multipliers for Laterally Loaded Pile Groups in Granular Soil Using 3D Nonlinear Finite Element Model

2020 ◽  
Vol 11 (1) ◽  
pp. 26
Author(s):  
Muhammad Bilal Adeel ◽  
Muhammad Asad Jan ◽  
Muhammad Aaqib ◽  
Duhee Park
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Design Guidelines ◽  
American Petroleum Institute ◽  
Winkler Foundation ◽  
Group Effect ◽  
Pile Groups ◽  
Element Analysis ◽  
Laterally Loaded Pile ◽  
Laterally Loaded

The behavior of laterally loaded pile groups is usually accessed by beam-on-nonlinear-Winkler-foundation (BNWF) approach employing various forms of empirically derived p-y curves and p-multipliers. Averaged p-multiplier for a particular pile group is termed as the group effect parameter. In practice, the p-y curve presented by the American Petroleum Institute (API) is most often utilized for piles in granular soils, although its shortcomings are recognized. In this study, we performed 3D finite element analysis to develop p-multipliers and group effect parameters for 3 × 3 to 5 × 5 vertically squared pile groups. The effect of the ratio of spacing to pile diameter (S/D), number of group piles, varying friction angle (φ), and pile fixity conditions on p-multipliers and group effect parameters are evaluated and quantified. Based on the simulation outcomes, a new functional form to calculate p-multipliers is proposed for pile groups. Extensive comparisons with the experimental measurements reveal that the calculated p-multipliers and group effect parameters are within the recorded range. Comparisons with two design guidelines which do not account for the pile fixity condition demonstrate that they overestimate the p-multipliers for fixed-head condition.

Investigation on the free vibration behavior of sandwich conical shells with reinforced cores

2021 ◽  
pp. 109963622110204
Author(s):  
Mehdi Zarei ◽  
Gholamhossien Rahimi ◽  
Davoud Shahgholian-Ghahfarokhi
Keyword(s):  
Free Vibration ◽  
Orientation Angle ◽  
Element Model ◽  
Filament Winding ◽  
Vertex Angle ◽  
Sandwich Shell ◽  
Cross Sectional ◽  
Conical Shells ◽  
Vibration Behavior ◽  
Axial Forces

The free vibration behavior of sandwich conical shells with reinforced cores is investigated in the present study using experimental, analytical, and numerical methods. A new effective smeared method is employed to superimpose the stiffness contribution of skins with those of the stiffener in order to achieve equivalent stiffness of the whole structure. The stiffeners are also considered as a beam to support shear forces and bending moments in addition to the axial forces. Using Donnell’s shell theory and Galerkin method, the natural frequencies of the sandwich shell are subsequently derived. To validate analytical results, experimental modal analysis (EMA) is further conducted on the conical sandwich shell. For this purpose, a method is designed for manufacturing specimens through the filament winding process. For more validation, a finite element model (FEM) is built. The results revealed that all the validations were in good agreement with each other. Based on these analyses, the influence of the cross-sectional area of the stiffeners, the semi-vertex angle of the cone, stiffener orientation angle, and the number of stiffeners are investigated as well. The results achieved are novel and can be thus employed as a benchmark for further studies.

scholarly journals Modeling Building Stock Development

2021 ◽  
Vol 13 (2) ◽  
pp. 723
Author(s):  
Antti Kurvinen ◽  
Arto Saari ◽  
Juhani Heljo ◽  
Eero Nippala
Keyword(s):  
Model Development ◽  
Housing Demand ◽  
Quality Data ◽  
Building Stock ◽  
Test Arena ◽  
Climate Targets ◽  
Wide Range ◽  
Key Variables ◽  
The Impact

It is widely agreed that dynamics of building stocks are relatively poorly known even if it is recognized to be an important research topic. Better understanding of building stock dynamics and future development is crucial, e.g., for sustainable management of the built environment as various analyses require long-term projections of building stock development. Recognizing the uncertainty in relation to long-term modeling, we propose a transparent calculation-based QuantiSTOCK model for modeling building stock development. Our approach not only provides a tangible tool for understanding development when selected assumptions are valid but also, most importantly, allows for studying the sensitivity of results to alternative developments of the key variables. Therefore, this relatively simple modeling approach provides fruitful grounds for understanding the impact of different key variables, which is needed to facilitate meaningful debate on different housing, land use, and environment-related policies. The QuantiSTOCK model may be extended in numerous ways and lays the groundwork for modeling the future developments of building stocks. The presented model may be used in a wide range of analyses ranging from assessing housing demand at the regional level to providing input for defining sustainable pathways towards climate targets. Due to the availability of high-quality data, the Finnish building stock provided a great test arena for the model development.

Contribution of Lamb wave modes in the formation of higher order modes cluster (HOMC) guided waves

2021 ◽  
pp. 095440622110424
Author(s):  
Z Abbasi ◽  
F Honarvar
Keyword(s):  
Finite Element ◽  
Wave Packet ◽  
Lamb Wave ◽  
Guided Waves ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Wave Modes

In recent years, Higher Order Modes Cluster (HOMC) guided waves have been considered for ultrasonic testing of plates and pipes. HOMC guided waves consist of higher order Lamb wave modes that travel together as a single nondispersive wave packet. The objective of this paper is to investigate the effect of frequency-thickness value on the contribution of Lamb wave modes in an HOMC guided wave. This is an important issue that has not been thoroughly investigated before. The contribution of each Lamb wave mode in an HOMC guided wave is studied by using a two-dimensional finite element model. The level of contribution of various Lamb wave modes to the wave cluster is verified by using a 2D FFT analysis. The results show that by increasing the frequency-thickness value, the order of contributing modes in the HOMC wave packet increases. The number of modes that comprise a cluster also increases up to a specific frequency-thickness value and then it starts to decrease. Plotting of the cross-sectional displacement patterns along the HOMC guided wave paths confirms the shifting of dominant modes from lower to higher order modes with increase of frequency-thickness value. Experimental measurements conducted on a mild steel plate are used to verify the finite element simulations. The experimental results are found to be in good agreement with simulations and confirm the changes observed in the level of contribution of Lamb wave modes in a wave cluster by changing the frequency-thickness value.

A Multi-Modality Image Data Collection Protocol for Full Body Finite Element Model Development

2009 ◽  
Author(s):  
F. Scott Gayzik ◽  
Craig A. Hamilton ◽  
Josh C. Tan ◽  
Craig McNally ◽  
Stefan M. Duma ◽  
...  
Keyword(s):  
Finite Element ◽  
Data Collection ◽  
Finite Element Model ◽  
Model Development ◽  
Image Data ◽  
Element Model ◽  
Full Body

An Analytical Method of Analyzing the Heat Conduction for the Unequal Cross-Section Straight Fin

2013 ◽  
Vol 365-366 ◽  
pp. 1211-1216
Author(s):  
Fan Zhang ◽  
Peng Yun Song
Keyword(s):  
Heat Conduction ◽  
Cross Section ◽  
Analytical Method ◽  
Thermal Analyses ◽  
Cross Sectional ◽  
Cross Section Area ◽  
Section Area ◽  
Calculation Results ◽  
The Cross ◽  
Analytical Expressions

The cross-section area of straight fin is often considered to be equal in the thermal analyses of straight fin, but sometimes it is unequalin actual situation. Taking a straight fin with two unequal cross-sectional areas as an example,an analytical method of heat conduction for unequal section straight fin is presented. The analytical expressions of temperature field and heat dissipating capacity about the fin,which has a smaller cross-section area near the fin base and a larger one, is obtained respectively. The calculation results of the unequal cross-section are fully consistent with the equal area one, so the method is proved right. The results show that the larger the cross section areanear the base,the better is the heat transfer, and the temperature at the base with larger cross-section area is lower than that with smaller cross-section area when the amount of heat is fixed.

scholarly journals A novel strain sensor using a microchannel embedded in PDMS

2018 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Angelica Campigotto ◽  
Stephane Leahy ◽  
Ayan Choudhury ◽  
Guowei Zhao ◽  
Yongjun Lai
Keyword(s):  
Finite Element ◽  
Rotation Angle ◽  
Strain Sensor ◽  
Element Model ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Sectional Area ◽  
Cross Sectional ◽  
Higher Sensitivity

A novel, inexpensive, and easy-to-use strain sensor using polydimethylsiloxane (PDMS)  was developed. The sensor consists of a microchannel that is partially filled with a coloured liquid and embedded in a piece of PDMS. A finite element model was developed to optimize the geometry of the microchannel to achieve higher sensitivity. The highest gauge factor that was measured experimentally was 41. The gauge factor was affected by the microchannel’s square cross-sectional area, the number of basic units in the microchannel, and the inlet and outlet configuration. As a case study, the developed strain sensors were used to measure the rotation angle of the wrist and finger joints.

scholarly journals Numerical and Experimental Study of Cross-Sectional Effects on the Mixing Performance of the Spiral Microfluidics

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1470
Author(s):  
Omid Rouhi ◽  
Sajad Razavi Bazaz ◽  
Hamid Niazmand ◽  
Fateme Mirakhorli ◽  
Sima Mas-hafi ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Study ◽  
Large Angle ◽  
Element Model ◽  
Channel Length ◽  
Cross Sectional ◽  
Flow Rates ◽  
Lab On Chip ◽  
Mixing Performance ◽  
Dean Flow

Mixing at the microscale is of great importance for various applications ranging from biological and chemical synthesis to drug delivery. Among the numerous types of micromixers that have been developed, planar passive spiral micromixers have gained considerable interest due to their ease of fabrication and integration into complex miniaturized systems. However, less attention has been paid to non-planar spiral micromixers with various cross-sections and the effects of these cross-sections on the total performance of the micromixer. Here, mixing performance in a spiral micromixer with different channel cross-sections is evaluated experimentally and numerically in the Re range of 0.001 to 50. The accuracy of the 3D-finite element model was first verified at different flow rates by tracking the mixing index across the loops, which were directly proportional to the spiral radius and were hence also proportional to the Dean flow. It is shown that higher flow rates induce stronger vortices compared to lower flow rates; thus, fewer loops are required for efficient mixing. The numerical study revealed that a large-angle outward trapezoidal cross-section provides the highest mixing performance, reaching efficiencies of up to 95%. Moreover, the velocity/vorticity along the channel length was analyzed and discussed to evaluate channel mixing performance. A relatively low pressure drop (<130 kPa) makes these passive spiral micromixers ideal candidates for various lab-on-chip applications.

Sign in / Sign up

Export Citation Format

Share Document