Experimental Determination of Stress Concentrations in Composite Laminates and their Effects on Damage Evolution

2006 ◽  
Vol 5-6 ◽  
pp. 383-390
Author(s):  
D.T.G. Katerelos ◽  
C. Galiotis
Keyword(s):  
Composite Laminates ◽  
Space Structures ◽  
Civil Infrastructure ◽  
Structural Elements ◽  
Stress Concentrations ◽  
Structural Element ◽  
Wide Range ◽  
Fail Safe ◽  
Circular Notch

Composite laminates are used for the construction of a wide range of products; from civil infrastructure to aeronautical or space structures. Since all these structures cannot be built at once, but they are composed by several structural elements connected in various patterns, the problem of stress concentrations strikes importantly. Additionally, the structures are often designed in a “fail safe” manner, which bespeaks the damage tolerance of the material. This means that the structural element and the structure are called to operate in the presence of various forms of damage. Damage locations within a structural element or a structure cause stress rising. In the present paper experimental investigation of the stress concentration arising in composite laminates, (a) around a circular notch and (b) due to damage onset and growth during their lifetime, is presented. The experimental results are compared to analytical model predictions.

scholarly journals Structural vehicle impact loading

2013 ◽  
Vol 11 (3) ◽  
pp. 285-292
Author(s):  
Dragoslav Stojic ◽  
Stefan Conic
Keyword(s):  
Impact Analysis ◽  
Impact Loads ◽  
Structural Elements ◽  
Structural Element ◽  
Static Loads ◽  
Equivalent Static Loads ◽  
Vehicle Impact ◽  
Dynamic Forces ◽  
Force Intensity

In contemporary design, vehicle impact into the structures is paid great attention since they can be dominant, depending on the type of structure. The key issue in the vehicle impact analysis is the proper determination of intensity and way of action of dynamic forces on the structural element and its behavior after the imparted load. The Eurocodes, in the annexes provide recommendations for determination of force intensity depending on mass and velocity of the colliding vehicle. Equivalent static loads causing approximate effects on the structural elements are used as quite approximate and efficient methods. The paper comprises the analysis of deformation of columns having the same characteristics, exposed to impact loads via the equivalent static loads, depending on the stress state in columns, and a comparative analysis has been done.

Design Curves for High-Cycle Fatigue Loaded Structural Elements

2013 ◽  
Vol 752 ◽  
pp. 135-144 ◽  
Author(s):  
Zsuzsanna Koncsik ◽  
János Lukács
Keyword(s):  
High Cycle Fatigue ◽  
Empirical Method ◽  
Fatigue Tests ◽  
Structural Elements ◽  
Cycle Fatigue ◽  
Structural Element ◽  
Fatigue Design ◽  
Structural Details ◽  
Important Design

Frequently, the cause of the failure of different structures or structural elements is the cyclic loading. Both fatigue design curves and methods for determination of these curves can be found in the literature. Even so, there are structural details whereabouts executing of examinations is necessary. The aims of the study are as follows: to give a short summary of important design curves can be found in different standards or specifications; and to demonstrate of own high cycle fatigue tests on a soldered structural element and the comparing of our results and the results of an empirical method.

scholarly journals ANALYSIS OF THE STATE OF SERVICEABILITY IN THE PROCESS OF WEAR OF ELEMENTS DURING THE OPERATION OF OIL AND GAS PRODUCTION EQUIPMENT

2021 ◽  
Vol 08 (04) ◽  
pp. 87-94
Author(s):  
Sevda Aliyeva Sevda Aliyeva
Keyword(s):  
Oil And Gas ◽  
Production Equipment ◽  
Gas Production ◽  
The State ◽  
Structural Elements ◽  
Structural Element ◽  
Oil And Gas Production ◽  
Total Utility ◽  
Generalized Indicator

The generalized indicator of useful use, depending on the state of individual elements of oil-producing equipment, characterizes the ability of this equipment to perform its function during operation at optimal working time. The generalized indicator of the useful use of operational equipment can be described as the calculated sum of the indicator of the useful use of individual equipment elements. If, during operation, the oil-producing equipment retains its operability due to frequent replacement of its structural and non-structural elements, then such operational equipment is considered by users as outdated. Operating equipment can be divided into 6 categories according to the indicators of suitability. The article analyzes the state of useful use of equipment and, as a result, the total utility of equipment is calculated in accordance with the indicators of useful use by category, and graphs of changes in the state of useful use are constructed. Based on the study of the graphs of the useful use of equipment, it was proposed to conduct an analysis in the following areas: • Evaluation of the design and technological perfection of the equipment by users according to important new parameters. • Determination of equipment compliance with wear standards during operation. Keywords: structural element, wear theory, the usefulness of jam, categories, schedule of changes, reliability.

scholarly journals Kajian Analisis Respon Struktur Bangunan Baja di Bawah Pengaruh Kombinasi Beban Termal (Kebakaran) dan Beban Angin. (Hal. 13-25)

2019 ◽  
Vol 5 (2) ◽  
pp. 13
Author(s):  
Amatulhay Pribadi
Keyword(s):  
Thermal Load ◽  
Stress Ratio ◽  
Steel Structure ◽  
Structural Elements ◽  
Structural Element ◽  
Temperature Load ◽  
Critical Thermal Load ◽  
Steel Properties

ABSTRAKBeban termal yang terjadi pada bangunan dapat mengakibatkan degradasi pada struktur baja dan menyebabkan keruntuhan. Penelitian ini menganalisis pengaruh beban termal disertai beban angin terhadap respon dari struktur bangunan baja lima belas lantai yang berfungsi sebagai perkantoran dengan mempertimbangkan degradasi propertis baja, reduksi beban hidup dan beban mati tambahan, serta kecepatan penanganan pemadaman. Simulasi terbagi menjadi tiga kasus yaitu penanganan pemadaman kebakaran cepat, penanganan pemadaman kebakaran lambat, dan penentuan beban termal kritis. Analisis struktur dilakukan dengan bantuan software ETABS. Hasil simulasi kebakaran menunjukkan semakin tinggi temperatur maka stress ratio dari elemen struktur makin membesar. Pada penentuan beban termal kritis diperoleh bahwa besar beban termal yang dapat menyebabkan minimal satu elemen struktur utama mengalami kegagalan pada umumnya berbeda pada lantai level bawah, tengah, dan atas. Pada studi kasus ini diperoleh beban temperatur kritis paling besar yaitu pada lantai level atas.Kata kunci: beban termal, degradasi propertis baja, kegagalan struktur ABSTRACTThermal load on the building can lead into the degradation of steel structure and cause collapse. This study analyze the effect of thermal along with wind loads on the response of fifteen stories steel structure building which serves as an office by considering the degradation of steel properties, the reduction of live load and super imposed dead load, and the speed of handling the extinguishing. This simulation is divided into three cases which are fast handling of extinguishing, slow handling of extinguishing, and the determination of the critical thermal load. Structural analysis will be done using the ETABS software. The result of fire simulation showed that when the temperature is higher, the stress ratio of structural elements will also expand. In the determination of the critical thermal load, it is obtained that the thermal loads which can cause failure in minimum one major structural element are generally different at the bottom, middle, and top level of stories. In this case study, the highest critical temperature load is on the top level.Keywords: thermal load, steel properties degradation, structure failure

scholarly journals THE RESEARCH OF EMPATHIC ABILITIES IN PRIMARY SCHOOL CHILDREN AS A STRUCTURAL ELEMENT OF THE CATEGORY “COMPASSION OF THE PUPIL”

2016 ◽  
Vol 2 ◽  
pp. 66
Author(s):  
Victoria Guseva
Keyword(s):  
Primary School ◽  
School Children ◽  
System Approach ◽  
Primary School Children ◽  
Structural Elements ◽  
Structural Element ◽  
Wide Range

The article deals with one aspect of the problems of development compassion in children. It outlines from positions of the system approach are researched empathic abilities of primary school children as one of the structural elements (substructures) in the category “compassion pupil”. The article contains the results of diagnosing the level of empathic abilities of primary school children. We have installed that a child with a developed ability to empathy tends more to the manifestation of gracious behavior and only 14% of primary school children are predisposed to the implementation of the merciful act.The article is intended for a wide range of readers and those, who are interested in pedagogy. 

scholarly journals NFLUENCE OF FAT PHASE ONTECHNOLOGICALLY IMPORTANT INDICATORS OF ICE CREAM PLOMBIR WITHOUT EMULSIFIERS

Food systems ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 4-11 ◽  
Author(s):  
T. V. Shobanova ◽  
A. A. Tvorogova
Keyword(s):  
Milk Fat ◽  
Practical Importance ◽  
Food Additives ◽  
Ice Cream ◽  
Structural Elements ◽  
Structural Element ◽  
Optimal Value ◽  
High Dispersity ◽  
Fat Particles

The determination of the technological functionality of milk fat particles in terms of their effect on the nucleation in ice cream plombir with a mass fraction of milk fat of at least 15% was the aim of the study. this work was carried out to justify the possibility of producing ice cream without emulsifiers — components that stabilize the air phase. It has been established that milk fat, with content of at least 15% in the ice cream, as a structural element of the system, positively influences the effective viscosity, which optimal value is necessary for the distribution of structural elements in ice cream. Besides the particles of milk fat in plombir are partially demulsified and there-fore are involved in the stabilization of the air phase because of their presence in a higher quantity if to compare with other types of ice cream due to its fragile protein-lipid shell. It promotes also the nucleation of ice crystals, thus ensuring their high dispersity. As stabilizers of the structure the products of physical modification are used, which firmly hold water in the structure, including after temperature fluctuations. the practical importance of the research was found in the development of ice cream plombir technology without the use of emulsifiers — a product without food additives or with a limited use of them.

Materials Diagnostics: Non-Destructive Identification of Degraded Areas of Microstructure

2014 ◽  
Vol 223 ◽  
pp. 348-354
Author(s):  
Jan T. Bonarski
Keyword(s):  
Functional Materials ◽  
Structural Elements ◽  
Structural Element ◽  
Experimental Conditions ◽  
Near Surface ◽  
Materials Engineering ◽  
Laboratory Techniques ◽  
Wide Range ◽  
Challenging Research ◽  
Non Destructive

The influence of material anisotropy on the exploitation performance of structural elements is recognized still insufficiently. The state seems to be the more evident if we consider that each type of materials inhomogeneity is not neutral in relation to its properties. In this field, carefully selected characteristics – the kind of microstructure diagnostics – delivers valuable data for the identification and quantification of desired material parameters deciding its usability. A separate problem is a spatial distribution of the parameters, which is an important feature of advanced, multi-functional materials with gradient-or/and layered structure. Further stages of the microstructure diagnostics covering the prediction of material behaviour in exploitation conditions and the estimation of the time of safe exploitation are still challenging research problems.The enumerated aspects of materials diagnostics require experimental data registered for the representative sample and suitable methods of data processing. Laboratory techniques and modelling procedures utilized in contemporary materials engineering deliver a wide range of computer-aided methodology, enabling one to obtain valuable characteristics of material, including crystallographic texture, residual stresses, phase composition, and crystallite size. In addition to methodological, experimental conditions play an important role in the outlined microstructure diagnostics. Both aspects are evident in the case of the identification of a subtle field of stresses resisted in the near-surface layer or in coating-substrate interface where a non-destructive way of examination is demanded. This work presents a selected non-destructive investigation of degraded areas of materials, recognized as critical from the viewpoint of the behaviour of a specific structural element in exploitation conditions.

STRUCTURAL RELIABILITY ANALYSIS BASED ON P-BOXES

2020 ◽  
Vol 92 (6) ◽  
pp. 51-58
Author(s):  
S.A. SOLOVYEV ◽  
Keyword(s):  
Probability Distribution ◽  
Reliability Analysis ◽  
Structural Reliability ◽  
Epistemic Uncertainty ◽  
Random Variable ◽  
Strength Criterion ◽  
Structural Elements ◽  
Structural Element ◽  
Limit States ◽  
Distribution Shape

The article describes a method for reliability (probability of non-failure) analysis of structural elements based on p-boxes. An algorithm for constructing two p-blocks is shown. First p-box is used in the absence of information about the probability distribution shape of a random variable. Second p-box is used for a certain probability distribution function but with inaccurate (interval) function parameters. The algorithm for reliability analysis is presented on a numerical example of the reliability analysis for a flexural wooden beam by wood strength criterion. The result of the reliability analysis is an interval of the non-failure probability boundaries. Recommendations are given for narrowing the reliability boundaries which can reduce epistemic uncertainty. On the basis of the proposed approach, particular methods for reliability analysis for any structural elements can be developed. Design equations are given for a comprehensive assessment of the structural element reliability as a system taking into account all the criteria of limit states.

DINAMIKA POLITIK PERSETUJUAN BERSAMA TENTANG PENETAPAN DESA ADAT DI KABUPATEN ROKAN HULU TAHUN 2014

2017 ◽  
Vol 15 (1) ◽  
pp. 21
Author(s):  
Haryo Suganda ◽  
Raja Muhammad Amin
Keyword(s):  
Regulatory Region ◽  
Field Research ◽  
Analysis Techniques ◽  
Political Dynamics ◽  
Political Interests ◽  
Wide Range ◽  
Information Method ◽  
Qualitative Descriptive ◽  
The Village

This study is motivated the identification of policies issued by the regional Governmentof Rokan Hulu in the form of Regulatory region number 1 by 2015 on the determination of thevillage and Indigenous Village. Political dynamics based on various interests against themanufacture of, and decision-making in the process of formation of the corresponding localregulations determination of Indigenous Villages in the Rokan Hulu is impacted to a verysignificantamount of changes from the initial draft of the number i.e. 21 (twenty one) the villagebecame Customary 89 (eighty-nine) the Indigenous Villages who have passed. Type of thisresearch is a qualitative descriptive data analysis techniques. The research aims to describe theState of the real situation in a systematic and accurate fact analysis unit or related research, aswell as observations of the field based on the data (information). Method of data collectionwas done with interviews, documentation, and observations through fieldwork (field research).The results of the research on the process of discussion of the draft local regulations andmutual agreement about Designation of Indigenous Villages in the Rokan Hulu is, showed thatthe political dynamics that occur due to the presence of various political interests, rejectionorally by Villagers who were judged to have met the requirements of Draft Regulations to beformulated and the area for the set to be Indigenous Villages, and also there is a desire fromsome villages in the yet to Draft local regulations in order to set the Indigenous village , there isa wide range of interests of these aspects influenced the agreement to assign the entire localVillage which is in the Rokan Hulu become Indigenous village, and the village of Transmigrationinto administrative Villages where the initiator of the changes in the number of IndigenousVillages in the Rokan Hulu it is the desire of the local Government of its own.

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