塑性诱导的加热:重新审视基于能源的变量模型.
Christoph Hartmann1, Michael Obermeyer1
1Chair of Metal Forming and Casting, Technical University of Munich, Walther-Meissner-Strasse 4, 85748 Garching near Munich, Germany.
Materials (Basel, Switzerland)
|March 13, 2024
概括
这项研究提出了一种新方法,用位移场来估计塑性变形过程中产生的热量. 该方法改善了在制造过程中对工具磨损的预测.
科学领域:
- 材料科学 材料科学 材料科学
- 机械工程 机械工程
- 计算力学 计算力学 计算力学
背景情况:
- 了解塑料变形过程中的温度变化对于制造工艺设计和预测工具磨损至关重要.
- 现有的实验和数值研究往往给出了关于可塑性诱导加热的矛盾结果.
- 准确估计热力学合对于可靠的模拟是必不可少的.
研究的目的:
- 分析直接从位移场中估计可塑性诱导加热的方法.
- 提出一种替代的计算方法来建模热力学行为.
- 为了提高预测塑性变形期间温度演变的准确性.
主要方法:
- 对合热力学问题的基于能量的变量公式的分析.
- 开发一种替代的纯热有限元模拟方法.
- 纳入热粘性塑料构成性行为 (约翰逊-库克模型).
- 使用基于泰勒-昆尼系数的热源术语来表示塑料工作转化为热量的部分.
主要成果:
- 拟议的替代方法提供了一种实际方法,用于从位移数据中估计可塑性诱导的加热.
- 该方法将应变和应变速率数据与热力学动机的热转换模型相结合.
- 与一些现有的方法相比,这种方法提供了一种更一致和可靠的方法来分析温度演变.
结论:
- 开发的有限元模拟方法有效地估计了利用位移场的可塑性诱导的加热.
- 这项工作有助于更准确地建模材料加工中的热力学现象.
- 这些发现可以帮助优化制造工艺,提高工具磨损预测.
相关概念视频
01:20Mechanisms of Heat Transfer II
3.2K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.2K
01:14Mechanisms of Heat Transfer I
4.2K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
4.2K
01:14Mechanisms of Heat Transfer
324
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
324
01:12Temperature Dependent Deformation
147
In a nonhomogeneous rod made up of steel and brass, restrained at both ends and subjected to a temperature change, several steps are involved in calculating the stress and compressive load. Due to the problem's static indeterminacy, one end support is disconnected, allowing the rod to experience the temperature change freely. Next, an unknown force is applied at the free end, triggering deformations in the rod's steel and brass portions. These deformations are then calculated and added...
147
01:19Mechanism of heat transfer
1.2K
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
1.2K
01:21Plastic Behavior
197
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and...
197