Alat Kejuruteraan Percuma
Kalkulator Kekuatan Tegangan & Ricih Bolt
Calculate the ultimate tensile load of metric bolts from ISO 898-1 property-class data, plus a simplified shear capacity estimate. Select bolt size and property class.
Kalkulator ini dibangunkan dan disahkan oleh pasukan kejuruteraan Vibromera, pengeluar instrumen pengimbangan mudah alih Balanset.
Keputusan
Beban Tegangan Muktamad
Daya tegangan maksimum yang boleh ditahan oleh bolt sebelum patah:
- Rm — kekuatan tegangan muktamad (MPa), daripada kelas sifat
- As — luas tegasan tegangan (mm²), daripada ISO 898-1 / ISO 261
Shear Capacity (Simplified Estimate)
ISO 898-1 defines the tensile and proof-load properties of bolts — it does tidak specify shear strength. The value shown here is a widely used simplified engineering estimate that takes shear strength as approximately 60% of tensile strength (based on the von Mises criterion, τ ≈ 0.58 σ):
Untuk ricih berganda, darabkan dengan 2 (dua satah ricih).
⚠️ Shear design note: Actual shear capacity depends on whether the shear plane passes through the threads or the unthreaded shank, on joint slip and plate bearing, and on fatigue loading. Design codes define their own values — e.g. Eurocode 3 (EN 1993-1-8) uses Fv = αv × fub × A with αv = 0.6 for classes 4.6, 5.6 and 8.8 but 0.5 for classes 4.8, 5.8, 6.8 and 10.9, together with partial safety factors. Always verify shear-loaded joints against the applicable structural or mechanical design code, not this simplified estimate alone.
Kelas Hartanah mengikut ISO 898-1
| Kelas | Rm (MPa) | Rp0.2 (MPa) | Penggunaan Biasa |
|---|---|---|---|
| 4.6 | 400 | 240 | Kekuatan rendah, tujuan umum |
| 5.8 | 520 | 420 | Struktur, tidak dimuatkan terlebih dahulu |
| 8.8 | 800 | 640 | Automotif, jentera (paling biasa) |
| 10.9 | 1040 | 940 | Struktur kekuatan tinggi |
| 12.9 | 1220 | 1100 | Kekuatan maksimum (keluli aloi) |
Contoh Praktikal
Diberi: Bolt M10, kelas sifat 8.8, ricih tunggal
As = 58.0 mm², Rm = 800 MPa
Ft = 800 × 58.0 = 46,400 N = 46.4 kN
Fs = 0.6 × 800 × 58.0 = 27,840 N = 27.8 kN
⚠️ Nota: Ini adalah kapasiti muktamad tanpa faktor keselamatan. Gunakan faktor keselamatan yang sesuai (biasanya 2–3 untuk statik, 4–6 untuk kelesuan) untuk tujuan reka bentuk.
The tensile stress area (As) is the effective cross-sectional area used to calculate the tensile load capacity of a threaded fastener. It is smaller than the nominal shank area because it accounts for the thread root geometry. Values are tabulated in ISO 898-1.
Ultimate tensile load is Ft = Rm × As, where Rm is the ultimate tensile strength (from the property class) and As is the tensile stress area. For example, a class 8.8 bolt has Rm = 800 MPa.
The first number (8) represents 1/100th of the minimum ultimate tensile strength in MPa (800 MPa). The second number (8) is 10× the ratio of yield to ultimate strength (0.8). So yield ≈ 800 × 0.8 = 640 MPa.
ISO 898-1 does not specify shear strength — it covers tensile and proof-load properties only. A common simplified estimate takes shear strength as 60% of tensile strength: Fs = 0.6 × Rm × As, based on the von Mises yield criterion. Design codes such as Eurocode 3 (EN 1993-1-8) apply their own factors (0.6 or 0.5 depending on property class) plus safety factors. For double shear (two planes), multiply by 2.
Proof load is the maximum force without permanent deformation (elastic limit). Ultimate tensile strength is the maximum force before fracture. Proof load stress is approximately 90% of yield strength for most property classes.
Prosedur yang diterangkan pada halaman ini telah dibangunkan dan diuji di lapangan oleh pasukan Vibromera menggunakan Balanset-1A, iaitu pengimbang dua saluran mudah alih dan penganalisis getaran untuk pengimbangan rotor di tapak.
Instrumen dan perisian pengimbangan medan profesional. Digunakan di lebih 50 buah negara.
