Terms of Use & Disclaimer

[Terms of Use & Disclaimer]

1. Theoretical Calculation Results

The values calculated by this simulator (such as deflection and bending stress) are simplified theoretical reference values based on structural mechanics under initial elastic conditions. They do not guarantee structural safety under actual operating environments or configurations.

2. Long-Term Creep Deformation

The calculated values indicate immediate initial deflection upon applying a load. Under continuous, long-term static loading, timber undergoes viscoelastic creep, which may cause deflection to progress to approximately 1.5 to 2.0 times the initial calculated value over time. For long-term installations, please design with sufficient margins in material thickness and structure.

3. Practical Limits of Joints and Fixity Conditions

The "Fixed-Fixed" option in this simulator assumes theoretically complete end fixity. In actual furniture or racking structures, loaded side uprights or columns tend to bow inward, and mechanical joints (such as screws or dowels) allow minor displacement. Consequently, complete rigid fixity (Fixed-Fixed) is rarely achieved in practice, and real-world behavior typically operates as a semi-rigid support between "Simply Supported" and "Fixed-Fixed" conditions.

4. Timber Properties, Material Variability, and Environmental Factors

Natural wood and timber-based materials exhibit variations in Young's Modulus (Modulus of Elasticity) of approximately ±20% depending on moisture content, knots, annual ring density, and grain orientation. In addition, material strength fluctuates with changes in ambient temperature and humidity (moisture absorption and desorption).

5. Limitation of Liability

The site owners and administrators accept no liability whatsoever for any accidents, damages, breakage, injuries, or losses arising from the use of this simulator or from structures and furniture built based on its calculation results. Fabrication and installation should be carried out at your own risk based on the judgment of individuals with technical expertise.

免責事項(日本語版)

【ご利用上の注意・免責事項】

  1. 計算結果について本シミュレーターで算出される値(たわみ量・曲げ応力など)は、構造力学に基づく理論式(初期弾性状態)を用いた簡易的な参考値です。実際の使用環境や構造における安全性を保証するものではありません。
  2. 経年変化(クリープ現象)による誤差計算値は荷物を載せた瞬間の初期たわみを示しています。長期間荷重をかけ続けると、木材の粘塑性(クリープ現象)により、時間の経過とともに計算値の約1.5倍〜2.0倍までたわみが進行する場合があります。長期設置の場合は、厚みや構造に十分な余裕を持たせた設計を行ってください。
  3. 接合部・固定条件の現実的限界シミュレーター上の「両端固定」は理論上の完全固定を前提としています。実際の家具やラック構造では、荷重がかかることで側板(柱)が内側に引き寄せられてしなったり、ビス・ダボ等の接合部にわずかな遊びが生じたりするため、完全な固定状態(両端固定)にはなりません。実際の挙動は「両端支持」と「両端固定」の中間程度(半固定)となります。
  4. 木材の物性・個体差および環境要因天然木および木質材料は、含水率・節の有無・年輪密度・木目の方向等によってヤング率(縦弾性係数)が±20%程度変動します。また、周囲の温度・湿度の変化(吸放湿)によっても強度が変化します。
  5. 免責範囲本シミュレーターの利用、または計算結果に基づいて製作された構造物・家具等によって生じた事故、損害、破損、怪我等につきましては、当サイトおよび管理者は一切の責任を負いかねます。製作・施工の際は専門知識を持った方の判断のもと、自己責任にてご実施ください。
Timber Deflection Calculator

Timber Deflection Calculator

mm
mm
kgf
Max Deflection (Elastic)
0.00 mm
Deflection Ratio (L / N)
L / 0
Max Bending Stress
0.00 MPa
Area Moment of Inertia (I)
0 cm⁴
Status: OK (Safe under normal conditions)
⚠️ Engineering Notes & Practical Discrepancies
  • Long-Term Creep Deformation:
    The calculated values reflect immediate short-term elastic deflection. Under long-term static loading (e.g., heavy books, equipment), timber undergoes viscoelastic creep, increasing total deflection by approximately 1.5 to 2.0 times over time.
  • Joint Rigidity and Frame Deflection (Fixed Support Limits):
    Even if a board is screwed or dadoed into side panels, loaded side uprights or rack columns tend to deflect inward or bow. Consequently, true "Fixed-Fixed" conditions are rarely achieved, operating practically as a semi-rigid support between simple and fixed constraints.
  • Moisture Content and Humidity:
    High ambient humidity increases wood moisture content, reducing the Modulus of Elasticity (E) and causing greater deflection than calculated under dry conditions.
  • Natural Material Variance:
    Solid timber and laminated boards exhibit variations in knots, grain, and density. Actual Young's Modulus values can fluctuate by ±20% from reference averages.
  • Grain Orientation:
    Calculations assume continuous longitudinal grain along the span. Edge-glued joints or irregular grain paths may reduce overall flexural strength.