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您的检索式：作者名="Mojtaba Rahimi"
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| 1 | Constitutive model for monotonic and cyclic responses of loosely cemented sand formations显示文摘This paper presents a model to simulate the monotonic and cyclic behaviours of weakly cemented sands.An elastoplastic constitutive model within the framework of bounding surface plasticity theory is adopted to predict the mechanical behaviour of soft sandstone under monotonic and cyclic loadings. In this model, the loading surface always passes through the current stress state regardless of the type of loading. Destruction of the cementation bonds by plastic deformation in the model is considered as the primary mechanism responsible for the mechanical degradation of loosely cemented sands/weak rock.To model cyclic response, the unloading plastic and elastic moduli are formulated based on the loading/reloading plastic and elastic moduli. The proposed model was implemented in FLAC2D and evaluated against laboratory triaxial tests under monotonic and cyclic loadings, and the model results agreed well with the experimental observations. For cyclic tests, hysteresis loops are captured with reasonable accuracy. | Mojtaba Rahimi Dave Chan Alireza Nouri | 2018 | Journal of Rock Mechanics and Geotechnical Engineering2018，10，4： | 3 |
| 2 | Review of Proposed Stress-dilatancy Relationships and Plastic Potential Functions for Uncemented and Cemented Sands显示文摘Stress-dilatancy relationship or plastic potential function are crucial components of every elastoplastic constitutive model developed for sand or cemented sand.This is because the associated flow rule usually does not produce acceptable outcomes for sand or cemented sand.Many formulas have been introduced based on the experimental observations in conventional and advanced plasticity models in order to capture ratio of plastic volumetric strain increment to plastic deviatoric strain increment(i.e.dilatancy rate).Lack of an article that gathers these formulas is clear in the literature.Thus,this paper is an attempt to summarize plastic potentials and specially stress-dilatancy relations so far proposed for constitutive modelling of cohesionless and cemented sands.Stress-dilatancy relation is usually not the same under compression and extension conditions.Furthermore,it may also be different under loading and unloading conditions.Therefore,the focus in this paper mainly places on the proposed stress-dilatancy relations for compressive monotonic loading.Moreover because plastic potential function can be calculated by integration of stress-dilatancy relationship,more weight is allocated to stress-dilatancy relationship in this research. | Mojtaba Rahimi | 2019 | Journal of Geological Research2019，1，2： | 0 |
| 3 | Road traffic deaths in Kashan region, Iran: An eight-year study (2006-2013)显示文摘这研究的 PurposeThe 目的是在 Kashan 区域分析道路交通死亡的趋势,伊朗,在八 years.MethodsThrough 的一个时期代表性的研究,在 Kashan 区域根据 ICD-10 在 V01V99 代码下面分类的所有道路交通死亡,中央伊朗,从2006年3月,到2013年3月和人口,数据从医药科学的 Kashan 大学的登记系统被收集。失去的生活(YLL ) 和死亡率的年关于事故的年龄,性和年被计算。有泊松木头线性的连接的概括线性模型(GLM ) 被用来在死亡 rate.ResultsDuring 上评估提及的变量的效果学习(8 年) 的时期, 928 个人(767 个人) 由于道路交通损害(RTI ) 死了。全部的 YLL 是 20,818。死亡率在 2006 年 3 月从 43.1 常常由于 RTI 被拒绝了到 21.1 每 100,000 在 2013 年 3 月。最高的死亡率在超过 60 岁的年龄组被发现并且在 0-14 岁的年龄组最低。死亡率和 YLL 比在女人在男人是更大的。泊松回归证明事故的年龄,性和年在死亡率上有重要效果( p ? | Mehrdad Mahdian Mojtaba Sehat Mohammad Reza Fazel Hossein Akbari Habibollah Rahimi Mahdi Mohammadzadeh | 2018 | Chinese Journal of Traumatology2018，21，1： | 0 |
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