scholarly journals Prediction of the Ultimate Strength of Notched and Unnotched IM7/977-3 Laminated Composites Using a Micromechanics Approach

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3491
Author(s):  
Manzar Masud ◽  
Moosa S. M. Al Kharusi ◽  
Muhammad Umair Ali ◽  
Aamir Mubashar ◽  
Shaik Javeed Hussain ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Test Data ◽  
Experimental Test ◽  
Laminated Composites ◽  
Compressive Load ◽  
Failure Criteria ◽  
Analysis Technique ◽  
Proposed Model ◽  
Tension And Compression ◽  
Failure Loads

This paper proposes a multi-scale analysis technique based on the micromechanics of failure (MMF) to predict and investigate the damage progression and ultimate strength at failure of laminated composites. A lamina’s representative volume element (RVE) is developed to predict and calculate constituent stresses. Damages that occurred in the constituents are calculated using separate failure criteria for both fiber and matrix. Subsequently, the volume-based damage homogenization technique is utilized to prevent the localization of damage throughout the total matrix zone. The proposed multiscale analysis procedure is then used to investigate the notched and unnotched behavior of three multi-directional composite layups, [30, 60, 90, −60, 30]2s, [0, 45, 90, −45]2s, and [60, 0, −60]3s, subjected to static tension and compression loading. The specimen is fabricated from unidirectionally reinforced composite (IM7/977-3). The prediction of ultimate strength at failure and equivalent stiffness are then benchmarked against the experimental test data. The comparative analysis with various failure models is also carried out to validate the proposed model. MMF demonstrated the capability to correctly predict the ultimate strength at failure for a range of multidirectional composites laminates under tensile and compressive load. The numerically predicted findings revealed a good agreement with the experimental test data. Out of the three investigated composite layups, the simulated results for the quasi-isotropic [0, 45, 90, −45]2S layup agreed extremely well with the experimental results with all the percentage errors within 10% of the measured failure loads.

Post-Yield Strain Tests of 20-in. Casing With Weld-on Connectors

1983 ◽  
Vol 105 (4) ◽  
pp. 554-559
Author(s):  
W. R. Blackstone ◽  
T. L. Blose ◽  
J. W. Galate
Keyword(s):  
Ultimate Strength ◽  
Test Data ◽  
Compression Test ◽  
Axial Strain ◽  
Full Scale ◽  
The State ◽  
Oil Well ◽  
Yield Strain ◽  
Tension And Compression ◽  
Permafrost Regions

Soils in permafrost regions may undergo significant subsidence due to thawing. Oil well surface casing embedded in such soils may be subjected to strains well beyond yield, whatever the casing properties might be. To deal with this, the State of Alaska has issued a specification defining the amount of axial strain that the casing, together with its connectors, must be able to withstand without parting. This paper presents full-scale tension and compression test data demonstrating that a particular weight and grade of 20-in. casing with premium weld-on connectors is a system exceeding those requirements. It is shown that, in tension, the material ultimate strength is reached first in the casing. Similarly, it is shown that, in compression, the casing buckles plastically before the connector fails.

scholarly journals A General Temperature-Dependent Stress–Strain Constitutive Model for Polymer-Bonded Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1393
Author(s):  
Xiaochang Duan ◽  
Hongwei Yuan ◽  
Wei Tang ◽  
Jingjing He ◽  
Xuefei Guan
Keyword(s):  
Composite Materials ◽  
Constitutive Model ◽  
Model Parameters ◽  
Temperature Dependent ◽  
Stress Strain ◽  
Proposed Model ◽  
Single Temperature ◽  
Testing Data ◽  
Bonded Composite ◽  
Tension And Compression

This study develops a general temperature-dependent stress–strain constitutive model for polymer-bonded composite materials, allowing for the prediction of deformation behaviors under tension and compression in the testing temperature range. Laboratory testing of the material specimens in uniaxial tension and compression at multiple temperatures ranging from −40 ∘C to 75 ∘C is performed. The testing data reveal that the stress–strain response can be divided into two general regimes, namely, a short elastic part followed by the plastic part; therefore, the Ramberg–Osgood relationship is proposed to build the stress–strain constitutive model at a single temperature. By correlating the model parameters with the corresponding temperature using a response surface, a general temperature-dependent stress–strain constitutive model is established. The effectiveness and accuracy of the proposed model are validated using several independent sets of testing data and third-party data. The performance of the proposed model is compared with an existing reference model. The validation and comparison results show that the proposed model has a lower number of parameters and yields smaller relative errors. The proposed constitutive model is further implemented as a user material routine in a finite element package. A simple structural example using the developed user material is presented and its accuracy is verified.

scholarly journals Experimental Study and Development of Design Formula for Estimating the Ultimate Strength of Curved Plates

2021 ◽  
Vol 11 (5) ◽  
pp. 2379
Author(s):  
Jeong-Hyeon Kim ◽  
Doo-Hwan Park ◽  
Seul-Kee Kim ◽  
Myung-Sung Kim ◽  
Jae-Myung Lee
Keyword(s):  
Aspect Ratio ◽  
Ultimate Strength ◽  
Large Deflection ◽  
Slenderness Ratio ◽  
Compressive Load ◽  
Element Analysis ◽  
Shipbuilding Industry ◽  
Design Formula ◽  
Deflection Analysis ◽  
Collapse Behavior

The curved plate has been extensively used as a structural member in many industrial fields, especially the shipbuilding industry. The present study investigated the ultimate strength and collapse behavior of the simply supported curved plate under a longitudinal compressive load. To do this, experimental apparatuses for evaluating the buckling collapse test of the curved plates was developed. Then, a series of buckling collapse experiments was carried out by considering the flank angle, slenderness ratio, and aspect ratio of plates. To examine the fundamental buckling and collapse behavior of the curved plate, elastoplastic large deflection analysis was performed using the commercial finite element analysis program. On the basis of both the experimental and FE analysis, the effects of the flank angle, slenderness ratio, and aspect ratio on the characteristics of the buckling and collapse behavior of the curved plates are discussed. Finally, the empirical design formula for predicting the ultimate strength of curved plates was derived. The proposed empirical formula is a good indicator for estimating the behavior of the curved plate.

Strength Prediction of Laminated Composites upon Independent Constituent Properties

2015 ◽  
Vol 665 ◽  
pp. 153-156
Author(s):  
Zheng Ming Huang ◽  
Li Min Xin
Keyword(s):  
Ultimate Strength ◽  
Input Data ◽  
Laminated Composites ◽  
Laminated Composite ◽  
Failure Detection ◽  
Strength Prediction ◽  
Internal Stresses ◽  
Matrix Properties

To predict ultimate strength of a laminated composite subjected to any load only using its constituent fiber and matrix properties measured independently, three challenging problems must be resolved with high success. First, internal stresses in the fiber and matrix must be accurately determined. Second, efficient failure detection for laminae and laminate upon the internal stresses must be achieved. Last but not the least, input data for the in-situ strengths of the constituents must be defined correctly from their original counterparts, as the former, different from the latter, are immeasurable. This presentation briefly summarizes our work on the targeted subject. All of the three issues have been systematically addressed with reasonable success.

MENINGKATKAN KETERAMPILAN MENULIS PUISI MELALUI MEDIA TULISAN BERGAMBAR (MEME) DI INSTAGRAM PADA PESERTA DIDIK KELAS VIII G SMPN 24 SURABAYA

Buana Bastra ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 26-31
Author(s):  
Prily Yulia Utomo Putri ◽  
Tri Indrayanti
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Test Data ◽  
Writing Skills ◽  
Test Results ◽  
Population Activity ◽  
Data Analysis Technique ◽  
Analysis Technique ◽  
Class Viii

This research is a research follow class by using the secound cycle that there is the first cycle and cycle II. On the cycle I and cycle II each cycle there four stage of the (1) planning, (2) implementation of action, (3) observations, and (4) reflection. Each cycle has two meetings in one week, namely the first meeting and the second meeting with the allocation 2 x 40 minutes of each meeting. Subject in research is learners class VIII G SMPN 24 Surabaya totaling 37 learners contained 16 learners men and 21 learners woman. This school is located in Jl. Kebraon Indah Permai Blok K/23 A Surabaya. Data collection techniques to use the observation and test, data analysis technique using the percentage of. Based on the results of data analysis, it can be concluded that using pictorial writing media on the meme on Instagram can improve the writing skills of class students VIII G SMPN 24 Surabaya. This can be seen from (1) population activity in the cycle I 84,61% on the cycle II 100%, (2) activity learners in cycle I 83,44% on the cycle II 90,20%, (3) the test results writing skills poerty in cycle I 56,73% one the cycle of II increased 83,70%.

scholarly journals PENINGKATAN KEMAMPUAN MENULIS TEKS PIDATO MENGGUNAKAN MODEL PEMBELAJARAN KUMON SISWA KELAS X MA AL-MUHAJIRIN TUGUMULYO

2019 ◽  
Vol 7 (2) ◽  
pp. 122
Author(s):  
DIAN RAMADAN LAZUARDI
Keyword(s):  
Data Analysis ◽  
Action Research ◽  
Data Collection ◽  
Test Data ◽  
Research Approach ◽  
Text Learning ◽  
Average Value ◽  
Action Research Approach ◽  
Analysis Technique ◽  
Classroom Action Research

AbstrakPenelitian ini bertujuan untuk meningkatkan kemampuan menulis teks pidato siswa kelas X MA Al-Muhajirin Tugumulyo menggunakan model pembelajaran kumon yang berjumlah 32 orang siswa. Penelitian ini menggunakan pendekatan penelitian tindakan kelas (classroom action research). Teknik pengumpulan data dalam penelitian ini�menggunakan teknik tes. Hasil data tes dianalisis dengan melihat nilai rata-rata peningkatan pada pratindakan, siklus I, dan siklus II. Teknik analisis data dilakukan dengan cara menjumlahkan skor dari indikator penilaian yang diperoleh siswa. Pada kegiatan pratindakan nilai rata-rata siswa sebesar 71,71% dengan ketuntasan sebesar 34,38% dengan jumlah siswa tuntas sebanyak 11 orang dan yang tidak tuntas sebanyak 21 orang. Tindakan siklus I, nilai rata-rata siswa 75,53 dan ketuntasan hanya mencapai 71,88% dengan jumlah siswa tuntas sebanyak 23 orang dan tidak tuntas sebanyak 9orang. Sedangkan pada siklus II nilai rata-rata mencapai 80,93 dengan jumlah siswa tuntas sebanyak 30 orang dan tidak tuntas 2 orang, berarti dari siklus I sampai siklus II meningkat sebesar 21,87%.. Simpulan, melalui model pembelajaran kumon kemampuan menulis teks pidato meningkat.Kata Kunci: Teks pidato, pembelajaran, kumon.AbstractThis study aims to improve the ability to write speech texts in class X MA Al-Muhajirin Tugumulyo using a kumon learning model of 32 students. This research uses a classroom action research approach. Data collection techniques in this study used test techniques. The results of the test data were analyzed by looking at the average value of the increase in pre-action, cycle I, and cycle II. Data analysis technique is done by adding up scores from assessment indicators obtained by students. In the pre-action activities the average value of students was 71.71% with completeness of 34.38% with the number of students as many as 11 people and as many as 21 people who did not complete. The first cycle of action, the average value of students 75.53 and completeness only reached 71.88% with the total number of students as many as 23 people and not as many as 9 people. While in cycle II the average value reached 80.93 with 30 students completing as many students and not completing 2 people, meaning that from cycle I to cycle II increased by 21.87%. increased.Keywords: Speech text, learning, kumon.

Mechanical Properties and Failure Criteria of Concrete under Biaxial Tension and Compression

2011 ◽  
Vol 261-263 ◽  
pp. 252-255 ◽  
Author(s):  
Jia Wei Yao ◽  
Yu Pu Song ◽  
Li Kun Qin ◽  
Ling Xia Gao
Keyword(s):  
Biaxial Tension ◽  
Failure Criteria ◽  
Test System ◽  
Proportional Loading ◽  
Dynamic Triaxial Test ◽  
Ordinary Concrete ◽  
Compression Failure ◽  
Tension And Compression ◽  
Compressive Tests ◽  
Good Agreement

Utilizing the large static-dynamic triaxial test system, 7 proportional loading biaxial tensile and compressive tests of concrete were conducted. The proportional loading paths are 0 (uniaxial compression), -0.05, -0.1, -0.15, -0.2, -0.25 and ∞ (uniaxial tension). Compressive and tensile strength were measured as well as the strains at two loading directions. Considering the ratio to tension and compression, failure criteria of ordinary concrete under biaxial tension and compression was established, which has a good agreement with test value.

PHOTOGRAMMETRY MEASUREMENTS OF INITIAL IMPERFECTIONS FOR THE ULTIMATE STRENGTH ASSESSMENT OF PLATES

2021 ◽  
Vol 156 (A4) ◽  
Author(s):  
A Cubells ◽  
Y Garbatov ◽  
C Guedes Soares
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Compressive Load ◽  
Initial Imperfection ◽  
Maximum Load ◽  
Surface Shape ◽  
Element Analysis ◽  
Strength Assessment ◽  
Load Carrying ◽  
Geometrical Imperfections

The objective of the present study is to develop a new approach to model the initial geometrical imperfections of ship plates by using Photogrammetry. Based on images, Photogrammetry is able to take measurements of the distortions of plates and to catch the dominant surface shape, including the deformations of the edges. Having this data, it is possible to generate faithful models of plate surface based on third order polynomial functions. Finally, the maximum load- carrying capacity of the plates is analysed by performing a nonlinear finite element analysis using a commercial finite element code. Three un-stiffened and four stiffened plates have been modelled and analysed. For each plate, two initial imperfection models have been generated one, based on photogrammetric measurements and the other, based on the trigonometric Fourier functions. Both models are subjected to the same uniaxial compressive load and boundary conditions in order to study the ultimate strength.

REINFORCEMENT OF AGEING SHIP STRUCTURES

2021 ◽  
Vol 160 (A3) ◽  
Author(s):  
D Chichì ◽  
Y Garbatov
Keyword(s):  
Monte Carlo Simulation ◽  
Finite Element ◽  
Ultimate Strength ◽  
Steel Plate ◽  
Plate Thickness ◽  
Compressive Load ◽  
Finite Element Models ◽  
Uniform Corrosion ◽  
Finite Element Analyses ◽  
Longitudinal Stiffeners

The objective of the present study is to investigate the possibility to recover the ultimate strength of a rectangular steel plate with a manhole shape opening subjected to a uniaxial compressive load and non-uniform corrosion degradation reinforced by additional stiffeners. Finite element analyses have been carried out to verify the possible design solutions. A total of four finite element models are generated, including 63 sub-structured models. The non-uniform corrosion has been generated by the Monte Carlo simulation. The reinforcement process covers three scenarios that include mounting of two longitudinal stiffeners, two longitudinal and two transverse stiffeners and the flange on the opening. The positioning of the stiffeners has also been studied. A total of 10 cases has been selected and tested for the numerical experiment. Three different assessments have been performed to evaluate the ultimate strength, weight and cost. Two additional studies on the effect of the plate thickness and slenderness have been also carried out.

Failure Criteria for Brittle Notched Specimens

2022 ◽  
Author(s):  
Young W. Kwon ◽  
Carlos Diaz-Colon ◽  
Stanley Defisher
Keyword(s):  
Elliptical Hole ◽  
Failure Criteria ◽  
Homogeneous Material ◽  
Carbon Fiber Composites ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Theoretical Predictions ◽  
Circular Holes ◽  
Failure Loads ◽  
Stress Models

Abstract Recently, new failure criteria were proposed for brittle materials to predict their failure loads regardless of the shapes of a notch or a crack in the material. This paper is to further evaluate the failure criteria for different shapes of notches and different materials. A circular hole, elliptical hole or crack-like slit with a different angle with respect to the loading direction was considered. Double circular holes were also studied. The materials studied were an isotropic material like polymethyl methacrylate (PMMA) as well as laminated carbon fiber composites. Both cross-ply and quasi-isotropic layup orientations were examined. The lamination theory was used for the composite materials so that they can be modelled as an anisotropic and homogeneous material. The test results were compared to the theoretical predictions using the finite element analysis with 2-D plane stress models. Both theoretical failure stresses agreed well with the experimental data for the materials and notch geometries studied herein.

Sign in / Sign up

Export Citation Format

Share Document