Analysis and Optimization of Automotive Structure’s Bending Stiffness Using Beam Elements

2012 ◽  
Author(s):  
Steven Tebby ◽  
Ahmad Barari ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Bending Stiffness ◽  
Major Drawback ◽  
Cross Sectional ◽  
Beam Elements ◽  
Complex Interactions ◽  
Design Changes ◽  
Vehicle Structure ◽  
Reaction Forces ◽  
Numerical Finite Element

Optimum design of vehicle’s structure is an important task in its development. The structure of a vehicle plays complex interactions with the other vehicle components and has significant impact on the performance of the vehicle. Structural design is usually completed by a complex iterative process. The design changes at late design stages effect many other parameters in the design of vehicle. Therefore, it is highly valuable for designers to employ simple but effective analyses at the early design stages. One method of analysis is using Simple Structural Surfaces. This method utilizes planar sheets to model the vehicle structure and allows the determination of the forces in each sheet. The major drawback of this method is its inability to easily determine deflections in a structure. To overcome this drawback a method that uses beam elements to represent the vehicle structure has been developed. This method uses a numerical finite element method and is able to determine unknown deflections and reaction forces as well as the internal loading on each member. This method can also be readily adapted to allow for parametric optimization for bending stiffness. The parameters associated with each beam element are the length, orientation and the beam characteristics of beams’ cross-sectional area and moment of inertia. An automated process is developed that manipulates some of these parameters to develop a structure that will have the greatest bending stiffness.

Using the Simple Structural Beam (SSB) Model to Optimize and Analyze Automotive Structures for Bending Stiffness and Natural Frequency

2014 ◽  
Author(s):  
Ian Wood ◽  
Ahmad Barari ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Natural Frequency ◽  
Early Stage ◽  
Dynamic Properties ◽  
Weight Ratio ◽  
Bending Stiffness ◽  
Beam Model ◽  
Beam Elements ◽  
Fundamental Natural Frequency ◽  
Stage Of Development ◽  
Vehicle Structure

When designing a vehicle structure, an optimum design is desired because the structure has a significant impact on its performance. The structure impacts other components in the vehicle as well. The designing process usually involves complex iteration. Analyses must be done at the early stage of the vehicle’s development (body-in-white) to minimize the amount of parameter changes needed during the late stage of development. Successfully implementing this strategy reduces the time and cost required to develop an effective vehicle structure. A method known as Simple Structural Surfaces can be used to model the vehicle structure as several planar sheets, as well as determine the forces in each sheet. The downside of using this method is that by using it, determining the deflections in the structure is difficult. In order to eliminate this difficulty, the vehicle is modeled as several beam elements instead. In this method, a finite element method is used to numerically solve for the deflections, reaction forces, and internal loading on each element of the structure. This Simple Structural Beam model can be adapted to allow optimization of the static property of the structure bending stiffness. Dynamic properties of the vehicle structure are also examined through vibration analysis, by determining the fundamental natural frequency of the structure. Vibration also has a large impact on the structure’s performance. The goal of the research is to obtain a design that will optimize the static and dynamic properties of the vehicle’s structure. In the beam elements, the parameters involved are the length, orientation, cross-sectional area, and moment of inertia. The optimizing process is automated and determines the beam dimensions with largest stiffness to weight ratio. The fundamental natural frequency calculated must be distant from the frequency of the engine, as resonance is also a concern for structural performance. Resonance occurs when the natural frequency of the system is equal to the frequency of a connecting component. This increases the amplitude of vibration significantly and is undesirable for any structural design.

scholarly journals An approach to the optimization of thin-walled cantilever open section beams

2007 ◽  
Vol 34 (4) ◽  
pp. 323-340 ◽  
Author(s):  
Nina Andjelic ◽  
Vesna Milosevic-Mitic
Keyword(s):  
Cross Section ◽  
Stress Constraints ◽  
Cross Sectional ◽  
Beam Elements ◽  
Geometrical Characteristics ◽  
Open Section ◽  
Optimal Values ◽  
Thin Walled ◽  
Constrained Torsion

An approach to the optimization of the thin-walled cantilever open section beams subjected to the bending and to the constrained torsion is considered. The problem is reduced to the determination of minimum mass, i.e. minimum cross-sectional area of structural thin-walled I-beam and channel-section beam elements for given loads, material and geometrical characteristics. The area of the cross-section is assumed to be the objective function. The stress constraints are introduced. Applying the Lagrange multiplier method the equations, whose solutions represent the optimal values of the ratios of the parts of the chosen cross-section, are formed. The obtained results are used for numerical calculation.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Profil Penyakit Malaria Di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

Profil Penyakit Malaria di Rumah Sakit Islam Siti Rahmah Padang Tahun 2018

2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi
Keyword(s):  
Observational Study ◽  
Frequency Distribution ◽  
Cross Section ◽  
Laboratory Tests ◽  
Age Group ◽  
Normal Range ◽  
Cross Sectional ◽  
West Sumatra ◽  
Severity Of The Disease

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Evaluating Virtual Care Experiences for Patients with Covid-19 Chief Complaints: Best-Practices Recommendations (Preprint)

2020 ◽  
Author(s):  
Saif Khairat ◽  
Malvika Pillai ◽  
Barbara Edson ◽  
Robert Gianforcaro
Keyword(s):  
Patient Experience ◽  
Wait Time ◽  
Secondary Outcome ◽  
Major Drawback ◽  
Cross Sectional ◽  
Average Wait Time ◽  
Adherence To Medication ◽  
Virtual Care ◽  
Chief Complaints ◽  
Virtual Visits

BACKGROUND Importance: Positive patient experiences are associated with illness recovery and adherence to medication. The shift toward virtual visits creates a need to understand the opportunities and challenges in providing a patient experience that is at least as positive as in-person visits. OBJECTIVE To evaluate the virtual care experience for patients with Covid-19 as their chief complaints. METHODS We conducted a cross-sectional study of the first cohort of patients with Covid-19 concerns in a virtual clinic. We collected data on all virtual visits between March 20-29, 2020. Outcomes: The main endpoints of this study were patient diagnosis, prescriptions received, referrals, wait time and duration, and satisfaction. The secondary outcome was the reported choice of alternative care options. RESULTS Of the 358 total virtual visits, 42 patients marked “Covid-19 Concern” as their chief complaint. Of those patients, 23 (54.8%) female patients, the average age of patients was 33.9 years, and 41 (97.7%) patients were seeking care for themselves and one (3.3%) visit was for a dependent. For all virtual visits, the average wait time (SD) was 157.2 (181.7) minutes and the average wait time (SD) for Covid-19 Concern visits was 177.4 (186.5) minutes. Covid-19 Concern phone visits had an average wait time (SD) of 180.1 (187.2), compared to 63.4 (34.4) minutes for Covid-19 Concern video visits. Thirteen (65%) patients rated their provider as “Excellent” with similar proportions among phone (64.3%) and video (66.7%). CONCLUSIONS This study evaluated the virtual experiences of patients with Covid-19 concerns. There were different experiences for patients depending on their choice of communication. Long wait times were a major drawback in the patient experience. We have learned from evaluating the experience of our first cohort of Covid-19 Concern patients.

scholarly journals Circulating bioactive sclerostin levels in an Austrian population-based cohort

2021 ◽  
Author(s):  
Katharina Kerschan-Schindl ◽  
Ursula Föger-Samwald ◽  
Andreas Gleiss ◽  
Stefan Kudlacek ◽  
Jacqueline Wallwitz ◽  
...  
Keyword(s):  
Serum Levels ◽  
Population Based ◽  
Negative Regulator ◽  
Total Serum ◽  
Mineral Density ◽  
Cross Sectional ◽  
Robust Parameter ◽  
Austrian Population ◽  
Different Levels

Summary Background Circulating serum sclerostin levels are supposed to give a good estimation of the levels of this negative regulator of bone mass within bone. Most studies evaluating total serum sclerostin found different levels in males compared to females and in older compared to younger subjects. Besides an ELISA detecting total sclerostin an ELISA determining bioactive sclerostin has been developed. The aim of this study was to investigate serum levels of bioactive sclerostin in an Austrian population-based cohort. Methods We conducted a cross-sectional observational study in 235 healthy subjects. Using the bioactive ELISA assay (Biomedica) bioactive sclerostin levels were evaluated. Results Serum levels of bioactive sclerostin were higher in men than in women (24%). The levels correlated positively with age (r = 0.47). A positive correlation could also be detected with body mass index and bone mineral density. Conclusion Using the ELISA detecting bioactive sclerostin our results are consistent with data in the literature obtained by different sclerostin assays. The determination of sclerostin concentrations in peripheral blood thus appears to be a robust parameter of bone metabolism.

scholarly journals Determination of cross-sectional void fraction in a two-phase water flow through a PVC pipe

2021 ◽  
Vol 655 (1) ◽  
pp. 012024
Author(s):  
O.H. Ajesi ◽  
M.B. Latif ◽  
S.T. Gbenu ◽  
C. A. Onumejor ◽  
M. K. Fasasi ◽  
...  
Keyword(s):  
Water Flow ◽  
Void Fraction ◽  
Two Phase ◽  
Cross Sectional ◽  
Flow Through ◽  
Pvc Pipe ◽  
Phase Water
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