تحلیل عددی نیروهای وارد بر تیغه دیسکی در فرآیند برش خطی سنگ با استفاده از روش المان محدود

از مهم‌ترین نتایج فرآیند برش خطی سنگ، برآورد دقیق و واقعی نیروهای برش وارد بر تیغه دیسکی است که می‌تواند مقدمه‌ای برای توسعه مدل‌هایی جهت پیش‌بینی عملکرد ماشین‌های حفر تمام مقطع تونل (tbm) باشد. در این مطالعه، مدلسازی عددی فرآیند برش سنگ با تیغه دیسکی با استفاده از کد تجاری المان محدود abaqus انجام شده است. برای راستی آزمایی مدل، از نتایج آزمایشگاهی آزمون برش خطی (lcm) محققان پیشین استفاده شده است. پس از حل مدل پیشنهادی، نیروهای وارد بر دیسک در سه راستا از مدل برش نتیجه‌ شد و میانگین هر کدام با استفاده از کدی که در محیط نرم‌افزار matlab توسعه داده شد، محاسبه‌ شده است. مقایسه نتایج آزمایشگاهی و مدلسازی عددی خطای 11.1 درصد برای میانگین نیروی نرمال، 5.6 درصد برای میانگین نیروی غلتشی، و 10 درصد برای میانگین نیروی جانبی را نشان می‌دهد. با مقایسه نتایج حاصل از مدلسازی عددی و آزمایش برش خطی، می‌توان نتیجه گرفت که مطابقت بسیار خوبی میان آنها برقرار است.

Numerical analysis of disc cutter forces in linear rock cutting procedure using finite element method

SummaryOne of the most important results of the linear rock cutting process is the accurate estimation of the cutting forces applied to the disc cutter which can be a prelude to the development of models for predicting the performance of all tunnel boring machines (TBM). In this study, numerical modeling of rock cutting process by a disc cutter using finite element code ABAQUS has been implemented. For model validation, the results of the linear cutting machine tests (LCM) by Previous researchers have been applied. After solving the proposed model, the forces on the disc were calculated in three directions of the rock cutting model and the mean of each force was calculated by a code that was developed in MATLAB software. Comparison of laboratory results and numerical modeling shows 11.1% error for the mean normal force, 5.6% error for the average rolling force, and 10% error for the average lateral force. By comparing the results of numerical modeling and linear cutting experiments, we can conclude that there is a good agreement between them. IntroductionIn this study, a numerical model of linear rock cutting process based on finite element method (commercial code  ABAQUS) was used. To validate the proposed model, Rostami’s (1997) linear rock cutting test on the Indiana limestone sample was used. Due to the unavailability of this rock sample, data from other texts were used to obtain input parameters to the model. A model assembly with a single disc cutter similar to laboratory test was simulated. By solving the proposed model, the forces applied to the cutter were calculated. Methodology and ApproachesIn order to model linear rock cutting procedures, Commercial finite element code ABAQUS/CAE was employed and for validating that, laboratory linear rock cutting test by Rostami (1997) was considered. Rock and disc cutter models was built in ABAQUS GUI module and to simulate rock behavior of rock model, a linear strength criterion was implemented in the model. Boundary Condition for disc cutter was similar to TBM’s working status with linear velocity of 2 meter per seconds and angular velocity of 9.3 radians per seconds. Results and ConclusionsModeling shear forces showed a similar trend to the experimental results. On the other hand, the comparison of the cutting forces of the experimental test with the numerical model results showed 11.1, 5.6 and 10% differences for the normal, rolling and lateral forces, respectively. This discrepancy seems to be due to the complexity and nonlinearity of the rockcutting problem and the impossibility of considering all the parameters governing to rockcutting process with a natural disc cutter. However, further analysis is being done by modeling on other rock samples to confirm the results.