What is stress concentration factor Kt?

Kt is the ratio of maximum local stress to nominal stress at a geometric discontinuity. Kt = σ_max / σ_nom. It depends only on geometry, not material. A circular hole in a wide plate under tension has Kt ≈ 3.0.

What causes stress concentrations?

Any abrupt change in geometry: holes, notches, fillets, keyways, threads, grooves, changes in cross-section. The stress flow lines crowd together at these features, increasing local stress.

How does Kt affect fatigue life?

Stress concentrations dramatically reduce fatigue life because fatigue cracks initiate at the point of highest stress. The fatigue notch factor Kf ≤ Kt accounts for material sensitivity: Kf = 1 + q(Kt-1), where q is the notch sensitivity factor.

How can stress concentrations be reduced?

Use generous fillet radii, avoid sharp corners, use gradual transitions, add relief grooves near shoulders, polish surfaces at critical points, and use shot peening to introduce beneficial compressive residual stress.

What is Peterson's Stress Concentration Factors?

Peterson's is the definitive reference book containing charts and equations for Kt values for hundreds of geometric configurations. It provides Kt as a function of geometric ratios (r/d, D/d, etc.) for tension, bending, and torsion loading.

मुक्त अभियांत्रिकी साधन

ताण एकाग्रता गुणांक गणक

सामान्य भूमितीसाठी Kt शोधा — प्लेटमधील छिद्र, शोल्डर फिलेट, U-नॉच — सुलभीकृत Peterson चार्ट डेटाचा वापर करून.

Peterson चार्ट्सKt शोध#173

भूमिती

रुंदी W किंवा D_major (mm)

छिद्र व्यास d किंवा d_minor (mm)

फिलेट/नॉच त्रिज्या r (mm)

नाममात्र ताण σ_nom (MPa, ऐच्छिक)

Quick presets

Results

ताण एकाग्रता गुणांक Kt

—

कमाल स्थानिक ताण σ_max

—

भूमितीय गुणोत्तर

—

ताण एकाग्रता गुणांक

सामान्य Kt मूल्ये

भूमिती	Kt श्रेणी
रुंद प्लेटमधील मध्यवर्ती छिद्र	~3.0 (small d/W)
शोल्डर फिलेट (D/d=2, r/d=0.1)	~1.8–2.5
U-नॉच	~1.5–3.5
परिघीय ग्रूव्ह	~1.5–3.0

⚠️ Note: ही सुलभीकृत curve-fit समीकरणांवर आधारित अंदाजित मूल्ये आहेत. अचूक मूल्यांसाठी Peterson Stress Concentration Factors पाहा किंवा FEA करा. Kt फक्त प्रत्यास्थ विश्लेषणासाठी आहे.

Stress Concentration Factor Kt Calculator | Vibromera

Published by Nikolai Shelkovenko on फेब्रुवारी 15, 2026 मार्च 5, 2026

Results

ताण एकाग्रता गुणांक

सामान्य Kt मूल्ये

Shop

आधार

Contact