scholarly journals Computational Determination of Macroscopic Mechanical and Thermal Material Properties for Different Microstructural Variants of Cast Iron

Author(s):  
Christoph Herrmann ◽  
Stefan Schmid ◽  
Daniel Schneider ◽  
Michael Selzer ◽  
Britta Nestler

The sensitivity of macroscopic mechanical and thermal properties of grey cast iron is computationally investigated for a variety of graphite microstructures over a wide temperature range. In order to represent common graphite microstructures according to DIN EN ISO 945-1, a synthetic approach is used to algorithmically generate simulation domains. The developed mechanical and thermal model is applied in a large simulation study. The study includes statistical volume elements of the graphite microstructures classes GG-15 and IA2 to IA5, with 10 v.-%, 11 v.-% and 12 v.-% graphite, respectively, for a temperature range from 20 °C to 750 °C. Homogenized macroscopic quantities such as the Young's moduli, Poisson's ratios, yield strengths and thermal conductivities are predicted for the different microstructure classes by applying simulation and data analysis tools of the research data infrastructure Kadi4Mat.

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1588
Author(s):  
Christoph Herrmann ◽  
Stefan Schmid ◽  
Daniel Schneider ◽  
Michael Selzer ◽  
Britta Nestler

The sensitivity of macroscopic mechanical and thermal properties of grey cast iron is computationally investigated for a variety of graphite morphologies over a wide temperature range. In order to represent common graphite morphologies according to EN ISO 945-1, a synthetic approach is used to algorithmically generate simulation domains. The developed mechanical and thermal model is applied in a large simulation study. The study includes statistical volume elements of the graphite morphology classes GJL-150 and IA2 to IA5, with 10, 11 and 12  v.−% of graphite precipitations, respectively, for a temperature range from 20 to 750 °C. Homogenised macroscopic quantities, such as the Young’s moduli, Poisson’s ratios, yield strengths and thermal conductivities, are predicted for different morphology classes by applying simulation and data analysis tools of the research data infrastructure Kadi4Mat. This is the first work to determine the mechanical and thermal properties of the morphology classes defined in EN ISO 945-1.


1998 ◽  
Vol 25 (2) ◽  
pp. 277-290 ◽  
Author(s):  
Michel Aubertin ◽  
Richard Simon

Most brittle materials show little straining at failure and an ultimate strength that depends upon loading geometry. The surface that defines failure in stress space has a characteristic shape that may be defined by an appropriate mathematical criterion. In this paper, the authors present a simple multiaxial criterion formulated from two quadric functions. Under conventional triaxial compression, the MSDP criterion reduces to the Mises-Schleicher criterion at low mean stress and it takes the shape of the conical Nadai-Drucker-Prager criterion at higher mean stress. The MSDP criterion can be expressed from the three principal stresses or from the usual invariantsI1, J2, and J3. It includes four characteristic parameters, each having a particular significance regarding material properties. The validity of the criterion is shown using experimental results taken from the literature on rock, concrete, and grey cast iron.Key words: failure, brittle materials, rock, concrete, cast iron.


1981 ◽  
Vol 42 (C5) ◽  
pp. C5-929-C5-934 ◽  
Author(s):  
P. Millet ◽  
R. Schaller ◽  
W. Benoit

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Astri Furqani ◽  
Hafidhah .

In this era, a lot of activities that can not be separated from the practice of cheating or fraud , no exception In the government . Inspektorat Sumenep is the leading institution of internal Local Government in preventing and detecting fraud in the Local Government appropiate Perbup Sumenep No. 29 of 2008 . Dinas Pendidikan Sumenep need attention on the issue . This is due to Dinas Pendidikan Sumenep an agency with the largest number of assets and managing large budgets . These conditions led to the formulation of the problem is How Inspektorat Sumenep role in preventing and detecting fraud in Dinas Pendidikan Sumenep. This study used a qualitative approach in which the focus of this study is Inspektorat role in preventing and detecting fraud at Dinas Pendidikan Sumenep . Primary data obtained by direct interviews with the parties directly related to the determination of the source of research data in a qualitative study using nonprobability sampling . The sampling technique used was purposive sampling . The conclusion of this study, role of the Inspektorat Sumenep in the prevention of fraud in Dinas Pendidikan Sumenep still not maximal . This is due to Inspektorat Sumenep not supervise from the planning / budgeting and not optimal in overseeing and assisting the implementation of the SPIP as an instrument of fraud prevention in Dinas Pendidikan Sumenep . The role of Inspektorat Sumenep in the detection of fraud in Dinas Pendidikan Sumenep done by conducting an audit of financial and asset management in each financial year.Keywords: fraud, government, inspektorat.


2016 ◽  
Vol 1 (2) ◽  
pp. 23
Author(s):  
MUNIRAH MUNIRAH ◽  
HUSAIN SYARIFUDDIN

This study aimed to describe the value of cohesion and coherence contained in the translation of the Qur'an surah Al Zalzalah. This study was a qualitative descriptive research, research data collection techniques using three techniques namely, inventory, rading and understanding, and record keeping. The data analysis used the coding of data, classification data, and the determination of the data. The results showed that the cohesion markers used in the translation of surah Al Zalzalah discourse are: 1) reference, 2) pronouns, ie pronouns second person, and third, the relative pronoun, the pronoun pointer, pen pronouns and pronouns owner, 3 ) conjunctions, namely temporal conjunctions, coordinating conjunctions, subordinating conjunctions, and conjunctions koorelatif, and 4) a causal ellipsis. It mean that there was a coherence in the translation of surah Al Zalzalah discourse are: the addition or addition, pronouns, repetition or repetition, match words or synonyms, in whole or in part, a comparison or ratio of conclusions or results. Keywords: Cohesion, Coherence, sura Al Zalzalah AbstrakPenelitian ini bertujuan untuk mendeskripsikan nilai kohesi dan koherensi yang terdapat dalam terjemahan Al-Qur’an surah Al Zalzalah. Jenis penelitian ini termasuk jenis penelitian deskriptif kualitatif, Teknik pengumpulan data penelitian menggunakan tiga teknik yakni, inventarisasi, baca simak, dan pencatatan. Teknik analisis data menggunakan pengodean data, pengklasifikasian data, dan penentuan data. Hasil penelitian menunjukkan bahwa pemarkah kohesi yang digunakan dalam wacana terjemahan surah Al Zalzalah adalah: 1) referensi, 2) pronomina, yaitu kata ganti orang kedua, dan ketiga, kata ganti penghubung, kata ganti penunjuk, kata ganti penanya dan kata ganti empunya, 3) konjungsi, yaitu konjungsi temporal, konjungsi koordinatif, konjungsi subordinatif, dan konjungsi koorelatif, dan 4) elipsis kausal. Sarana koherensi yang terdapat di dalam wacana terjemahan surah Al Zalzalah adalah: penambahan atau adisi, pronomina, pengulangan atau repetisi, padan kata atau sinonim, keseluruhan atau bagian, komparasi atau perbandingan simpulan atau hasil.Kata Kunci: Kohesi, Koherensi, surah Al Zalzalah


2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.


Sign in / Sign up

Export Citation Format

Share Document