Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-97-108
Vladimir A. Repin, Anastasiya V. Lukina, A. Strekalkin
An analysis of changing patterns of the values of member forces in a scissors truss, depending on the position of connections of its lower chords to the upper chords, is performed. Exploring effective truss structure designs in terms of balanced combination of maximum strength and minimum weight is a sustainable approach to a more rational use of building materials and the development of green construction. This determines the relevance of this area of research. The analysis of configurations of the truss under study was performed using the parameterized Maxwell - Cremona diagram. Such diagram is a visually informative tool in presenting the calculation results and it fully reflects the relationship between the member forces and the parameters of the structure. The research process was performed using the MS Excel spreadsheet editor. This eventually developed into a software tool for finding effective scissors truss designs, which has full potential for further improvement and development. Thus, the functionality of the tool can be easily expanded to designing scissors trusses made of various structural materials, as well as with various crosssectional shapes of its elements. The proposed approach to the calculation of such structures can serve as a basis for parameterization of trusses with other types of web.
本文分析了剪刀桁架中构件力值的变化规律，这种变化规律取决于下弦杆与上弦杆的连接位置。在最大强度和最小重量的平衡组合方面探索有效的桁架结构设计，是更合理地使用建筑材料和发展绿色建筑的一种可持续方法。这决定了这一研究领域的相关性。研究中的桁架配置分析是使用参数化麦克斯韦-克雷莫纳图进行的。这种图表是展示计算结果的直观信息工具，它充分反映了构件受力与结构参数之间的关系。研究过程使用 MS Excel 电子表格编辑器进行。它最终发展成为一个用于寻找有效剪刀桁架设计的软件工具，具有进一步改进和发展的充分潜力。因此，该工具的功能可以很容易地扩展到设计各种结构材料制成的剪刀桁架，以及各种截面形状的构件。所提出的此类结构的计算方法可作为其他类型腹杆桁架参数化的基础。
{"title":"Parameterization of Maxwell - Cremona Diagram for Determining Forces in Elements of a Scissors Truss","authors":"Vladimir A. Repin, Anastasiya V. Lukina, A. Strekalkin","doi":"10.22363/1815-5235-2024-20-2-97-108","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-97-108","url":null,"abstract":"An analysis of changing patterns of the values of member forces in a scissors truss, depending on the position of connections of its lower chords to the upper chords, is performed. Exploring effective truss structure designs in terms of balanced combination of maximum strength and minimum weight is a sustainable approach to a more rational use of building materials and the development of green construction. This determines the relevance of this area of research. The analysis of configurations of the truss under study was performed using the parameterized Maxwell - Cremona diagram. Such diagram is a visually informative tool in presenting the calculation results and it fully reflects the relationship between the member forces and the parameters of the structure. The research process was performed using the MS Excel spreadsheet editor. This eventually developed into a software tool for finding effective scissors truss designs, which has full potential for further improvement and development. Thus, the functionality of the tool can be easily expanded to designing scissors trusses made of various structural materials, as well as with various crosssectional shapes of its elements. The proposed approach to the calculation of such structures can serve as a basis for parameterization of trusses with other types of web.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" May","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-134-145
Vyacheslav N. Ivanov
A method of forming a curved orthogonal coordinate system on a plane and a technique of constructing new surface shapes with curved trapezoidal plans are presented. Multiple examples of curved trapezoidal plans based on different directrix curves and surfaces with the given plans, including combinations of surfaces with different conjugate directrix curves, are illustrated. The proposed technique of surface forming may be used in architecture and construction for development of thin-walled space structures in both urban and industrial buildings. But for the analysis of thin shells, geometric characteristics of the middle surface of the shell are usually used. Vector equation of surfaces with curved trapezoidal plan was used to obtain the formulas for the fundamental form coefficients and surface curvatures. Examples of calculation of the fundamental form coefficients and curvatures of surfaces with particular directrix curves and vertical coordinate functions are presented.
{"title":"Geometric Characteristics of Surfaces with Curved Trapezoidal Plan","authors":"Vyacheslav N. Ivanov","doi":"10.22363/1815-5235-2024-20-2-134-145","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-134-145","url":null,"abstract":"A method of forming a curved orthogonal coordinate system on a plane and a technique of constructing new surface shapes with curved trapezoidal plans are presented. Multiple examples of curved trapezoidal plans based on different directrix curves and surfaces with the given plans, including combinations of surfaces with different conjugate directrix curves, are illustrated. The proposed technique of surface forming may be used in architecture and construction for development of thin-walled space structures in both urban and industrial buildings. But for the analysis of thin shells, geometric characteristics of the middle surface of the shell are usually used. Vector equation of surfaces with curved trapezoidal plan was used to obtain the formulas for the fundamental form coefficients and surface curvatures. Examples of calculation of the fundamental form coefficients and curvatures of surfaces with particular directrix curves and vertical coordinate functions are presented.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" 17","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-109-119
Wisam H. Mohammed, S. Shambina, H. Ammash
This study investigated influence of varying waviness characteristics of fiber, represented by path amplitude Δ and different numbers of half sine waves k , on the elastic-plastic dynamic behaviour of laminated composite plates with variable fiber spacing. The analysis was based on the equations for action of constant axial dynamic loading and two-dimensional layered approach with classical first order shear deformation theory with five degrees of freedom per node, and it was performed with FORTRAN 94 programming language. Von-Karman’s assumptions were used for the discretization of the laminated plates to include geometric nonlinearity for nine-node Lagrangian isoperimetric quadrilateral elements. Complete bond between the layers was assumed with no delamination, which was based on first-order shear deformation theory. The Newmark implicit time integration method and Newton-Raphson iteration were simultaneously used to solve the nonlinear governing equation in conjunction. It was proven in the research that the nonlinear performance of the laminated composite plate was affected by the studied waviness parameters Δ and k , and also by the variable distribution pattern selected for this study.
本研究探讨了以路径振幅 Δ 和不同半正弦波数 k 表示的不同纤维波浪特性对纤维间距可变的层压复合板的弹塑性动态行为的影响。分析基于恒定轴向动载荷作用方程和二维分层方法，采用经典的一阶剪切变形理论，每个节点有五个自由度，分析使用 FORTRAN 94 编程语言进行。层压板的离散化采用了 Von-Karman 假设，包括九节点拉格朗日等周四边形元素的几何非线性。根据一阶剪切变形理论，假设层间完全粘合，没有分层。同时采用纽马克隐式时间积分法和牛顿-拉夫逊迭代法来求解非线性控制方程。研究证明，层压复合板的非线性性能受到所研究的波形参数 Δ 和 k 以及所选择的变量分布模式的影响。
{"title":"Effect of Sinusoidal Fiber Waviness on Non-Linear Dynamic Performance of Laminated Composite Plates with Variable Fiber Spacing","authors":"Wisam H. Mohammed, S. Shambina, H. Ammash","doi":"10.22363/1815-5235-2024-20-2-109-119","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-109-119","url":null,"abstract":"This study investigated influence of varying waviness characteristics of fiber, represented by path amplitude Δ and different numbers of half sine waves k , on the elastic-plastic dynamic behaviour of laminated composite plates with variable fiber spacing. The analysis was based on the equations for action of constant axial dynamic loading and two-dimensional layered approach with classical first order shear deformation theory with five degrees of freedom per node, and it was performed with FORTRAN 94 programming language. Von-Karman’s assumptions were used for the discretization of the laminated plates to include geometric nonlinearity for nine-node Lagrangian isoperimetric quadrilateral elements. Complete bond between the layers was assumed with no delamination, which was based on first-order shear deformation theory. The Newmark implicit time integration method and Newton-Raphson iteration were simultaneously used to solve the nonlinear governing equation in conjunction. It was proven in the research that the nonlinear performance of the laminated composite plate was affected by the studied waviness parameters Δ and k , and also by the variable distribution pattern selected for this study.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" October","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-159-169
S. Cheremnykh
The development of the construction industry in terms of the design and manufacture of shell structures of non-standard architectural forms made of materials with complex mechanical properties requires using modern integrated computer-aided design systems with step-by-step modeling of deformation of structural elements under operating conditions, as well as taking into account their subsequent behavior after accumulation of residual strains during plastic deformation. The purpose of the study is to simulate the process of plastic deformation of a thin-walled cylindrical shell made of 9X2 GOST 5950-2000 (Interstate Standard) steel under compression and torsion with theoretical calculations based on the general theory of elastoplastic processes by A.A. Ilyushin. The constitutive equations of the theory of elastoplastic processes by A.A. Ilyushin for complex loading path and deformation of materials in the deviatoric strain space are presented. Based on the presented solutions, according to the strain path of the 9X2 steel shell implemented in the model, the graphs showing the relation of the vector and scalar properties of the material to the arc length of the strain path are constructed. A conclusion is made about the degree of hardening of the material in question and its dependence on the magnitude of the angle of convergence at the kink point of the complex path. The graphs of changes in the constitutive plasticity functions with respect to the increments of the arc length of the strain path are presented.
{"title":"Deformation of Cylindrical Shell Made of 9X2 Steel Under Complex Loading","authors":"S. Cheremnykh","doi":"10.22363/1815-5235-2024-20-2-159-169","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-159-169","url":null,"abstract":"The development of the construction industry in terms of the design and manufacture of shell structures of non-standard architectural forms made of materials with complex mechanical properties requires using modern integrated computer-aided design systems with step-by-step modeling of deformation of structural elements under operating conditions, as well as taking into account their subsequent behavior after accumulation of residual strains during plastic deformation. The purpose of the study is to simulate the process of plastic deformation of a thin-walled cylindrical shell made of 9X2 GOST 5950-2000 (Interstate Standard) steel under compression and torsion with theoretical calculations based on the general theory of elastoplastic processes by A.A. Ilyushin. The constitutive equations of the theory of elastoplastic processes by A.A. Ilyushin for complex loading path and deformation of materials in the deviatoric strain space are presented. Based on the presented solutions, according to the strain path of the 9X2 steel shell implemented in the model, the graphs showing the relation of the vector and scalar properties of the material to the arc length of the strain path are constructed. A conclusion is made about the degree of hardening of the material in question and its dependence on the magnitude of the angle of convergence at the kink point of the complex path. The graphs of changes in the constitutive plasticity functions with respect to the increments of the arc length of the strain path are presented.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" November","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-120-133
Krishna Chapagain, Hemchandra Chaulagain
Most of the building stock in Nepal is based on masonry construction, which includes monumental, administrative, and residential structures. These structures are vulnerable during earthquakes, as evidenced by the massive structural damage, loss of human life, and property damage due to a lack of proper assessment and appropriate strengthening measures. An analysis of the seismic vulnerability of existing old Newari brick masonry buildings in the Pokhara Valley is presented. These buildings were built using indigenous knowledge and technology. The investigation is based on analytical studies, with some material properties obtained from field tests. Proper modeling of a masonry structure is crucial for reliable seismic resistance and structural design. However, modeling a real masonry structure is a challenging and computationally demanding task due to its complicated framework, requiring in-depth knowledge, realistic material properties, and relevant information. The aim of this research is to assess the seismic performance of old Newari masonry buildings using stress level and fragility curves. The research issues are addressed analytically through linear time history analysis using the finite element program-based software Sap 2000 v20. In dynamic analysis, numerical building models were subjected to three synthetic earthquakes. The performance status of the building based on various stress levels is evaluated, and weak regions are identified. The fragility curve of the structure is assessed, considering the ground motion parameters in the locality. The fragility function is plotted with the probability of failure at an interval of 0.10 g. The results of the analysis highlight that the studied structure is vulnerable compared to the codal provisions and standard recommendations.
尼泊尔的大部分建筑都是砖石结构，包括纪念性建筑、行政建筑和住宅建筑。由于缺乏正确的评估和适当的加固措施，这些建筑在地震中很容易受到损坏，造成大量的结构破坏、人员伤亡和财产损失。本文分析了博卡拉山谷现有老式纽瓦里砖砌体建筑的抗震脆弱性。这些建筑是利用本地知识和技术建造的。调查以分析研究为基础，并通过现场测试获得了一些材料属性。砌体结构的正确建模对于可靠的抗震和结构设计至关重要。然而，由于真实砌体结构的框架复杂，建模是一项极具挑战性且计算要求极高的任务，需要深入的知识、真实的材料属性和相关信息。本研究的目的是利用应力水平和脆性曲线评估老式纽瓦里砌体建筑的抗震性能。研究问题是通过使用基于有限元程序的软件 Sap 2000 v20 进行线性时间历程分析来解决的。在动态分析中，数值建筑模型经受了三次合成地震。根据不同的应力水平评估了建筑物的性能状况，并确定了薄弱区域。考虑到当地的地面运动参数，对结构的脆性曲线进行了评估。分析结果表明，与规范规定和标准建议相比，所研究的结构是脆弱的。
{"title":"Seismic Fragility Analysis of Existing Old Newari Brick Masonry Building in Pokhara Valley","authors":"Krishna Chapagain, Hemchandra Chaulagain","doi":"10.22363/1815-5235-2024-20-2-120-133","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-120-133","url":null,"abstract":"Most of the building stock in Nepal is based on masonry construction, which includes monumental, administrative, and residential structures. These structures are vulnerable during earthquakes, as evidenced by the massive structural damage, loss of human life, and property damage due to a lack of proper assessment and appropriate strengthening measures. An analysis of the seismic vulnerability of existing old Newari brick masonry buildings in the Pokhara Valley is presented. These buildings were built using indigenous knowledge and technology. The investigation is based on analytical studies, with some material properties obtained from field tests. Proper modeling of a masonry structure is crucial for reliable seismic resistance and structural design. However, modeling a real masonry structure is a challenging and computationally demanding task due to its complicated framework, requiring in-depth knowledge, realistic material properties, and relevant information. The aim of this research is to assess the seismic performance of old Newari masonry buildings using stress level and fragility curves. The research issues are addressed analytically through linear time history analysis using the finite element program-based software Sap 2000 v20. In dynamic analysis, numerical building models were subjected to three synthetic earthquakes. The performance status of the building based on various stress levels is evaluated, and weak regions are identified. The fragility curve of the structure is assessed, considering the ground motion parameters in the locality. The fragility function is plotted with the probability of failure at an interval of 0.10 g. The results of the analysis highlight that the studied structure is vulnerable compared to the codal provisions and standard recommendations.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141128197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-170-181
V.P. Agapov, A. Markovich, Prashanta Dkhar, Darya A. Golishevskaia
The purpose of the study is to examine the physical and mechanical characteristics of steel fiber-reinforced concrete under compression, including: modulus of elasticity, Poisson ratio, values of ultimate strains under compression, values of compressive strength with different percentages of dispersed reinforcement. An experimental investigation program, which included the production of cube samples measuring 100×100×100 mm, as well as a compression test under static loading, taking into account unloading from the region of inelastic deformations, was developed and carried out. Two types of steel fiber were chosen as dispersed reinforcement: hooked end and wave shape. The volume content of steel fiber in the cube samples was 0.5, 1.0, 1.5 and 2.0 %. As a result of the investigation, the strength and deformation characteristics of steel fiber reinforced concrete under compression were obtained. Based on the experimental data, actual strain diagrams of steel fiber reinforced concrete were constructed, taking into account the type of reinforcing fibers and the percentage of reinforcing fiber. Based on the obtained diagrams, a law of deformation of steel fiber reinforced concrete is proposed, which can be described by a polynomial function of the fourth order with constant coefficients that determine the shape of the stress-strain curve. The presented research results can be used in developing a methodology for physically nonlinear analysis of steel fiber reinforced concrete elements with a percentage of dispersed reinforcement from 0.5 to 2.0 %.
{"title":"Stress-Strain State of Steel Fiber-Reinforced Concrete under Compression Taking into Account Unloading from Inelastic Region","authors":"V.P. Agapov, A. Markovich, Prashanta Dkhar, Darya A. Golishevskaia","doi":"10.22363/1815-5235-2024-20-2-170-181","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-170-181","url":null,"abstract":"The purpose of the study is to examine the physical and mechanical characteristics of steel fiber-reinforced concrete under compression, including: modulus of elasticity, Poisson ratio, values of ultimate strains under compression, values of compressive strength with different percentages of dispersed reinforcement. An experimental investigation program, which included the production of cube samples measuring 100×100×100 mm, as well as a compression test under static loading, taking into account unloading from the region of inelastic deformations, was developed and carried out. Two types of steel fiber were chosen as dispersed reinforcement: hooked end and wave shape. The volume content of steel fiber in the cube samples was 0.5, 1.0, 1.5 and 2.0 %. As a result of the investigation, the strength and deformation characteristics of steel fiber reinforced concrete under compression were obtained. Based on the experimental data, actual strain diagrams of steel fiber reinforced concrete were constructed, taking into account the type of reinforcing fibers and the percentage of reinforcing fiber. Based on the obtained diagrams, a law of deformation of steel fiber reinforced concrete is proposed, which can be described by a polynomial function of the fourth order with constant coefficients that determine the shape of the stress-strain curve. The presented research results can be used in developing a methodology for physically nonlinear analysis of steel fiber reinforced concrete elements with a percentage of dispersed reinforcement from 0.5 to 2.0 %.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" January","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-182-194
Mikhail N. Voskresenskiy, Alena A. Kurdanova
Studying the nature of the occurrence and propagation of microseismic tremors has not lost its relevance over the past few decades. Currently, the analysis of microseisms is the basis of some engineering and geological studies, including those aimed at the inspection of structures of various purposes. The procedure for preparing and conducting surveys is governed by a system of regulatory documents. However, the current codes and specifications represent a general guide for assessing the operational properties of building structures. Therefore, specific survey methods need to be clarified and detailed. Describes the experiment of examining the building regarding the dynamics of frequency characteristics within 24 hours. The observation system was implemented in the form of 16 points, evenly distributed over the volume of the building. Spectral analysis based on FFT was carried out to identify the time intervals within the 24-hour period with a pronounced maximum and minimum level of man-induced impact on the studied subject. During the hours of maximum exposure, the spectra were correlated according to records of different duration in terms of the correspondence of frequency components. The necessary and sufficient duration of registration of microseismic vibrations was derived to determine the frequency of natural vibration of a building when the observation points are located on the lower and upper floors.
{"title":"Optimal Duration of Observations During Seismic Inspection of Buildings","authors":"Mikhail N. Voskresenskiy, Alena A. Kurdanova","doi":"10.22363/1815-5235-2024-20-2-182-194","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-182-194","url":null,"abstract":"Studying the nature of the occurrence and propagation of microseismic tremors has not lost its relevance over the past few decades. Currently, the analysis of microseisms is the basis of some engineering and geological studies, including those aimed at the inspection of structures of various purposes. The procedure for preparing and conducting surveys is governed by a system of regulatory documents. However, the current codes and specifications represent a general guide for assessing the operational properties of building structures. Therefore, specific survey methods need to be clarified and detailed. Describes the experiment of examining the building regarding the dynamics of frequency characteristics within 24 hours. The observation system was implemented in the form of 16 points, evenly distributed over the volume of the building. Spectral analysis based on FFT was carried out to identify the time intervals within the 24-hour period with a pronounced maximum and minimum level of man-induced impact on the studied subject. During the hours of maximum exposure, the spectra were correlated according to records of different duration in terms of the correspondence of frequency components. The necessary and sufficient duration of registration of microseismic vibrations was derived to determine the frequency of natural vibration of a building when the observation points are located on the lower and upper floors.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":"3 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-15DOI: 10.22363/1815-5235-2024-20-2-146-158
Gerard L. Gbaguidi Aisse, O. Aleshina, I. A. Mamieva
It is proved and illustrated that by taking the main frame of the surface, consisting of three plane curves placed in three coordinate planes, three different algebraic surfaces with the same rigid frame can be designed. For the first time, one three of new ruled surfaces in a family of five threes of ruled surfaces, formed on the basis of some shapes of hulls of river and see ships, which, in turn, are projected in the form of algebraic surfaces with a main frame of three superellipses or of three other plane curves, is under consideration in detail with a standpoint of differential geometry. The geometrical properties of the ruled surfaces taken as the middle surfaces of thin shells for industrial and civil engineering are presented. Analytical formulas for determination of force resultants with using the approximate momentless theory of shells of zero Gaussian curvature given by non-orthogonal conjugate curvilinear coordinates are offered for the first time. The results derived using these formulae will help to correct the results obtained by numerical methods.
{"title":"Geometric Investigation of Three Thin Shells with Ruled Middle Surfaces with the Same Main Frame","authors":"Gerard L. Gbaguidi Aisse, O. Aleshina, I. A. Mamieva","doi":"10.22363/1815-5235-2024-20-2-146-158","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-2-146-158","url":null,"abstract":"It is proved and illustrated that by taking the main frame of the surface, consisting of three plane curves placed in three coordinate planes, three different algebraic surfaces with the same rigid frame can be designed. For the first time, one three of new ruled surfaces in a family of five threes of ruled surfaces, formed on the basis of some shapes of hulls of river and see ships, which, in turn, are projected in the form of algebraic surfaces with a main frame of three superellipses or of three other plane curves, is under consideration in detail with a standpoint of differential geometry. The geometrical properties of the ruled surfaces taken as the middle surfaces of thin shells for industrial and civil engineering are presented. Analytical formulas for determination of force resultants with using the approximate momentless theory of shells of zero Gaussian curvature given by non-orthogonal conjugate curvilinear coordinates are offered for the first time. The results derived using these formulae will help to correct the results obtained by numerical methods.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":" August","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141127892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-15DOI: 10.22363/1815-5235-2024-20-1-73-83
Kirill V. Avdeev, Vladimir V. Bobrov, Mikhail A. Tuchin, E. V. Domarova, Nikita A. Kudryavtsev, Pavel V. Skakun
The study of the physical and mechanical properties of polycarbonate under various temperature conditions, taking into account its widespread use as a base material of monolithic polycarbonate systems in various climatic regions, will ensure a high degree of reliability of structures during operation in a wide temperature range. The authors of the article conducted a series of tensile tests of monolithic polycarbonate in the temperature range from -60 to +80 °C. The influence of temperature on the following characteristics of monolithic polycarbonate was evaluated: elongation at break, tensile yield strength, tensile stress at break, strains at the end of the elastic stage of the material. As a result of the conducted experimental studies, the relationship between the strength properties of monolithic polycarbonate and the operating temperature was revealed. The values of elongation at break at temperatures exceeding 15 °C for various samples generally correspond to the values obtained during tests conducted under standard conditions.
考虑到聚碳酸酯作为整体聚碳酸酯系统的基材在各种气候条件下的广泛应用，研究聚碳酸酯在各种温度条件下的物理和机械性能将确保结构在宽温度范围内运行时的高度可靠性。文章作者在 -60 至 +80 °C 的温度范围内对整体聚碳酸酯进行了一系列拉伸试验。评估了温度对整体聚碳酸酯以下特性的影响：断裂伸长率、拉伸屈服强度、断裂拉伸应力、材料弹性阶段结束时的应变。实验研究揭示了整体聚碳酸酯的强度特性与工作温度之间的关系。各种样品在温度超过 15 ° C 时的断裂伸长率值与在标准条件下进行测试时获得的值基本一致。
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Pub Date : 2024-03-15DOI: 10.22363/1815-5235-2024-20-1-84-93
Rashidbek M. Hudaykulov, Dilshod E. Aralov
Current modern trends in road construction are the increase in traffic intensity and the carrying capacity of motor transport, as well as the expansion of the road network, including local roads. These trends put forward the task of not only increasing the durability of road structures, but also the use of local materials and soils in the construction of highways. Several methods have been developed to strengthen the soils of the road base. A variety of surfactants, modifiers and additives are also produced to strengthen the roadbed. Many of them have not shown their effectiveness in practice. Therefore, there is a need for plenty laboratory and field studies on this topic. Laboratory studies were carried out to investigate the effect of the modifier on the roadbed soil. The type of soil and its maximum density were determined at optimal humidity. Based on this, cement and a modifier were introduced into the soil composition, density and compressive strength were determined. The results of a scanning electron microscope (SEM) were obtained to study the effect of the modifier on the roadbed soil. Laboratory studies and SEM-analysis have shown that the addition of a modifier to the soil leads to an increase in its maximum density, a significant increase in compressive strength and that the modifier serves to improve the binding properties by forming a crystalline bond with cement.
{"title":"Results of Laboratory Studies of Strengthening Subgrade Soil with Modifier","authors":"Rashidbek M. Hudaykulov, Dilshod E. Aralov","doi":"10.22363/1815-5235-2024-20-1-84-93","DOIUrl":"https://doi.org/10.22363/1815-5235-2024-20-1-84-93","url":null,"abstract":"Current modern trends in road construction are the increase in traffic intensity and the carrying capacity of motor transport, as well as the expansion of the road network, including local roads. These trends put forward the task of not only increasing the durability of road structures, but also the use of local materials and soils in the construction of highways. Several methods have been developed to strengthen the soils of the road base. A variety of surfactants, modifiers and additives are also produced to strengthen the roadbed. Many of them have not shown their effectiveness in practice. Therefore, there is a need for plenty laboratory and field studies on this topic. Laboratory studies were carried out to investigate the effect of the modifier on the roadbed soil. The type of soil and its maximum density were determined at optimal humidity. Based on this, cement and a modifier were introduced into the soil composition, density and compressive strength were determined. The results of a scanning electron microscope (SEM) were obtained to study the effect of the modifier on the roadbed soil. Laboratory studies and SEM-analysis have shown that the addition of a modifier to the soil leads to an increase in its maximum density, a significant increase in compressive strength and that the modifier serves to improve the binding properties by forming a crystalline bond with cement.","PeriodicalId":32610,"journal":{"name":"Structural Mechanics of Engineering Constructions and Buildings","volume":"21 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140240719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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