🧻 卷材长度Roll Length

使用说明与常见问题How-to & FAQ

「卷材长度」是什么？What is the Roll Length tool?

长度 ≈ π × 层数 × (外径+内径)/2（示意）。本地处理。可设置「外径」、「内径」、「厚度」。Length ≈ π × layers × (OD+ID)/2 (demo). Processed locally. Settings: Outer diameter, Inner diameter, Thickness.

如何使用「卷材长度」？How do I use the Roll Length tool?

在「卷材长度」中，填写「外径」、「内径」、「厚度」等参数，结果会随输入实时计算并显示在下方。In the Roll Length: Fill in "Outer diameter", "Inner diameter", "Thickness"; results are recalculated instantly as you type.

紧密？Tight wind?

示意平均周长，未计间隙。Mean-circumference demo - no gaps.

能举个计算实例吗？Can you show a worked example?

例如在「卷材长度」中填 外径 = 30，内径 = 5，厚度 = 0.1，结果区显示：层数示意：125；长度示意：6,872.2339For example, entering Outer diameter = 30, Inner diameter = 5, Thickness = 0.1 in the Roll Length gives: Layers demo: 125; Length demo: 6,872.2339

哪些输入会被检查？Which inputs are validated?

「卷材长度」会检查这些输入——「外径」、「内径」、「厚度」：必须填写，须大于 0；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Roll Length checks its inputs — "Outer diameter", "Inner diameter", "Thickness": required, must be greater than 0; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.

有哪些选项可以调整？What options can I adjust?

「卷材长度」的设置：「外径」默认 30；「内径」默认 5；「厚度」默认 0.1。每次生成结果都按当前设置处理。Settings in the Roll Length — "Outer diameter" default 30; "Inner diameter" default 5; "Thickness" default 0.1. The result always uses the current settings.

计算结果可以用于作业或工程吗？Can I use the results for homework or engineering?

「卷材长度」使用教科书标准公式（公式写在说明和常见问题中），适合学习和估算核对；涉及安全的工程设计请以规范和实测为准。The Roll Length uses standard textbook formulas (given in the description and FAQ), which is good for learning and checking estimates; for safety-critical engineering follow codes and measured values.

「卷材长度」免费吗？需要注册吗？Is the Roll Length free? Do I need an account?

「卷材长度」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Roll Length is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.